diff --git a/benchmarks/filesystem.bench.cpp b/benchmarks/filesystem.bench.cpp
index 3e49560..4c46444 100644
--- a/benchmarks/filesystem.bench.cpp
+++ b/benchmarks/filesystem.bench.cpp
@@ -1,7 +1,7 @@
 #include "benchmark/benchmark.h"
 #include "GenerateInput.hpp"
 #include "test_iterators.h"
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 static const size_t TestNumInputs = 1024;
 
diff --git a/test/libcxx/algorithms/half_positive.pass.cpp b/test/libcxx/algorithms/half_positive.pass.cpp
index ec2d57c..8be1fec 100644
--- a/test/libcxx/algorithms/half_positive.pass.cpp
+++ b/test/libcxx/algorithms/half_positive.pass.cpp
@@ -17,7 +17,7 @@
 #include <type_traits>
 
 #include "test_macros.h"
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 namespace {
 
diff --git a/test/libcxx/containers/gnu_cxx/hash_map.pass.cpp b/test/libcxx/containers/gnu_cxx/hash_map.pass.cpp
index 2c72acd..df41318 100644
--- a/test/libcxx/containers/gnu_cxx/hash_map.pass.cpp
+++ b/test/libcxx/containers/gnu_cxx/hash_map.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 void test_default_does_not_allocate() {
   DisableAllocationGuard g;
diff --git a/test/libcxx/containers/gnu_cxx/hash_set.pass.cpp b/test/libcxx/containers/gnu_cxx/hash_set.pass.cpp
index 6626fc6..307ba73 100644
--- a/test/libcxx/containers/gnu_cxx/hash_set.pass.cpp
+++ b/test/libcxx/containers/gnu_cxx/hash_set.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 void test_default_does_not_allocate() {
   DisableAllocationGuard g;
diff --git a/test/libcxx/containers/sequences/deque/spare_block_handling.pass.cpp b/test/libcxx/containers/sequences/deque/spare_block_handling.pass.cpp
index fb6c767..0db2f91 100644
--- a/test/libcxx/containers/sequences/deque/spare_block_handling.pass.cpp
+++ b/test/libcxx/containers/sequences/deque/spare_block_handling.pass.cpp
@@ -21,7 +21,7 @@
 #include <queue>
 
 #include "min_allocator.h"
-#include "rapid-cxx-test.hpp"
+#include "rapid-cxx-test.h"
 
 template <class Adaptor>
 struct ContainerAdaptor : public Adaptor {
diff --git a/test/libcxx/debug/containers/db_associative_container_tests.pass.cpp b/test/libcxx/debug/containers/db_associative_container_tests.pass.cpp
index e837da7..8ee62ae 100644
--- a/test/libcxx/debug/containers/db_associative_container_tests.pass.cpp
+++ b/test/libcxx/debug/containers/db_associative_container_tests.pass.cpp
@@ -22,7 +22,7 @@
 #include <set>
 #include <utility>
 #include <cassert>
-#include "container_debug_tests.hpp"
+#include "container_debug_tests.h"
 #include "test_macros.h"
 #include "debug_mode_helper.h"
 
diff --git a/test/libcxx/debug/containers/db_sequence_container_iterators.multithread.pass.cpp b/test/libcxx/debug/containers/db_sequence_container_iterators.multithread.pass.cpp
index 75b9c0d..fcdc45d 100644
--- a/test/libcxx/debug/containers/db_sequence_container_iterators.multithread.pass.cpp
+++ b/test/libcxx/debug/containers/db_sequence_container_iterators.multithread.pass.cpp
@@ -24,7 +24,7 @@
 #include <list>
 #include <thread>
 #include <vector>
-#include "container_debug_tests.hpp"
+#include "container_debug_tests.h"
 
 #include "test_macros.h"
 
diff --git a/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp b/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp
index 43f1dd9..68b41b2 100644
--- a/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp
+++ b/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp
@@ -22,7 +22,7 @@
 #include <list>
 #include <vector>
 #include <deque>
-#include "container_debug_tests.hpp"
+#include "container_debug_tests.h"
 #include "test_macros.h"
 #include "debug_mode_helper.h"
 
diff --git a/test/libcxx/debug/containers/db_string.pass.cpp b/test/libcxx/debug/containers/db_string.pass.cpp
index b6519df..8c39ccc 100644
--- a/test/libcxx/debug/containers/db_string.pass.cpp
+++ b/test/libcxx/debug/containers/db_string.pass.cpp
@@ -21,7 +21,7 @@
 #include <vector>
 
 #include "test_macros.h"
-#include "container_debug_tests.hpp"
+#include "container_debug_tests.h"
 #include "debug_mode_helper.h"
 
 using namespace IteratorDebugChecks;
diff --git a/test/libcxx/debug/containers/db_unord_container_tests.pass.cpp b/test/libcxx/debug/containers/db_unord_container_tests.pass.cpp
index 5ddbfa9..b5d1995 100644
--- a/test/libcxx/debug/containers/db_unord_container_tests.pass.cpp
+++ b/test/libcxx/debug/containers/db_unord_container_tests.pass.cpp
@@ -21,7 +21,7 @@
 #include <unordered_set>
 #include <utility>
 #include <cassert>
-#include "container_debug_tests.hpp"
+#include "container_debug_tests.h"
 #include "test_macros.h"
 #include "debug_mode_helper.h"
 
diff --git a/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp b/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp
index 730030f..dd6d621 100644
--- a/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp
+++ b/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp
@@ -45,7 +45,7 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/db_deallocate.pass.cpp b/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/db_deallocate.pass.cpp
index 2855ba1..8211e63 100644
--- a/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/db_deallocate.pass.cpp
+++ b/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/db_deallocate.pass.cpp
@@ -22,7 +22,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/libcxx/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/db_deallocate.pass.cpp b/test/libcxx/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/db_deallocate.pass.cpp
index e906192..ec8926b 100644
--- a/test/libcxx/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/db_deallocate.pass.cpp
+++ b/test/libcxx/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/db_deallocate.pass.cpp
@@ -22,7 +22,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/libcxx/input.output/filesystems/class.directory_entry/directory_entry.mods/last_write_time.sh.cpp b/test/libcxx/input.output/filesystems/class.directory_entry/directory_entry.mods/last_write_time.sh.cpp
index e24ae99..17b654e 100644
--- a/test/libcxx/input.output/filesystems/class.directory_entry/directory_entry.mods/last_write_time.sh.cpp
+++ b/test/libcxx/input.output/filesystems/class.directory_entry/directory_entry.mods/last_write_time.sh.cpp
@@ -15,13 +15,13 @@
 // RUN: %build -I%libcxx_src_root/src/filesystem
 // RUN: %run
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 #include "filesystem_common.h"
 
diff --git a/test/libcxx/input.output/filesystems/class.path/path.itr/iterator_db.pass.cpp b/test/libcxx/input.output/filesystems/class.path/path.itr/iterator_db.pass.cpp
index 9856000..2729e59 100644
--- a/test/libcxx/input.output/filesystems/class.path/path.itr/iterator_db.pass.cpp
+++ b/test/libcxx/input.output/filesystems/class.path/path.itr/iterator_db.pass.cpp
@@ -16,13 +16,13 @@
 // class path
 
 #define _LIBCPP_DEBUG 0
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <iterator>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 #include "debug_mode_helper.h"
 
 int main(int, char**) {
diff --git a/test/libcxx/input.output/filesystems/class.path/path.itr/reverse_iterator_produces_diagnostic.fail.cpp b/test/libcxx/input.output/filesystems/class.path/path.itr/reverse_iterator_produces_diagnostic.fail.cpp
index 5eb5cbd..1d21cb9 100644
--- a/test/libcxx/input.output/filesystems/class.path/path.itr/reverse_iterator_produces_diagnostic.fail.cpp
+++ b/test/libcxx/input.output/filesystems/class.path/path.itr/reverse_iterator_produces_diagnostic.fail.cpp
@@ -12,7 +12,7 @@
 
 // class path
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <iterator>
 
 
diff --git a/test/libcxx/input.output/filesystems/class.path/path.req/is_pathable.pass.cpp b/test/libcxx/input.output/filesystems/class.path/path.req/is_pathable.pass.cpp
index a80f02e..269b82d 100644
--- a/test/libcxx/input.output/filesystems/class.path/path.req/is_pathable.pass.cpp
+++ b/test/libcxx/input.output/filesystems/class.path/path.req/is_pathable.pass.cpp
@@ -20,14 +20,14 @@
 // * A character array, which points to a NTCTS after array-to-pointer decay.
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
 #include "min_allocator.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 using fs::__is_pathable;
 
diff --git a/test/libcxx/type_traits/convert_to_integral.pass.cpp b/test/libcxx/type_traits/convert_to_integral.pass.cpp
index 735609b..45aedb1 100644
--- a/test/libcxx/type_traits/convert_to_integral.pass.cpp
+++ b/test/libcxx/type_traits/convert_to_integral.pass.cpp
@@ -21,7 +21,7 @@
 #include <cstdint>
 #include <cassert>
 
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 #include "test_macros.h"
 
diff --git a/test/libcxx/utilities/optional/optional.object/triviality.abi.pass.cpp b/test/libcxx/utilities/optional/optional.object/triviality.abi.pass.cpp
index ce36603..8c7452b 100644
--- a/test/libcxx/utilities/optional/optional.object/triviality.abi.pass.cpp
+++ b/test/libcxx/utilities/optional/optional.object/triviality.abi.pass.cpp
@@ -24,7 +24,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 #include "test_macros.h"
 
diff --git a/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/disable_reduced_arity_initialization_extension.pass.cpp b/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/disable_reduced_arity_initialization_extension.pass.cpp
index 8e4cb52..803d3b8 100644
--- a/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/disable_reduced_arity_initialization_extension.pass.cpp
+++ b/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/disable_reduced_arity_initialization_extension.pass.cpp
@@ -22,7 +22,7 @@
 #include <system_error>
 
 #include "test_macros.h"
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "MoveOnly.h"
 
 #if defined(_LIBCPP_ENABLE_TUPLE_IMPLICIT_REDUCED_ARITY_EXTENSION)
diff --git a/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/enable_reduced_arity_initialization_extension.pass.cpp b/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/enable_reduced_arity_initialization_extension.pass.cpp
index f012d4c..9624eb8 100644
--- a/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/enable_reduced_arity_initialization_extension.pass.cpp
+++ b/test/libcxx/utilities/tuple/tuple.tuple/tuple.cnstr/enable_reduced_arity_initialization_extension.pass.cpp
@@ -24,7 +24,7 @@
 #include <system_error>
 
 #include "test_macros.h"
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "MoveOnly.h"
 
 
diff --git a/test/libcxx/utilities/utility/pairs/pairs.pair/assign_tuple_like.pass.cpp b/test/libcxx/utilities/utility/pairs/pairs.pair/assign_tuple_like.pass.cpp
index 7895072..27281fa 100644
--- a/test/libcxx/utilities/utility/pairs/pairs.pair/assign_tuple_like.pass.cpp
+++ b/test/libcxx/utilities/utility/pairs/pairs.pair/assign_tuple_like.pass.cpp
@@ -20,7 +20,7 @@
 #include <memory>
 #include <cassert>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 #include "test_macros.h"
 
diff --git a/test/libcxx/utilities/utility/pairs/pairs.pair/piecewise.pass.cpp b/test/libcxx/utilities/utility/pairs/pairs.pair/piecewise.pass.cpp
index 259aa64..d324a4d 100644
--- a/test/libcxx/utilities/utility/pairs/pairs.pair/piecewise.pass.cpp
+++ b/test/libcxx/utilities/utility/pairs/pairs.pair/piecewise.pass.cpp
@@ -20,7 +20,7 @@
 #include <type_traits>
 #include <utility>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
index 3b20fbd..2f012d5 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 // #if TEST_STD_VER > 17
 // TEST_CONSTEXPR bool test_constexpr() {
diff --git a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
index 2e181cf..027dedc 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 // #if TEST_STD_VER > 17
 // TEST_CONSTEXPR bool test_constexpr() {
diff --git a/test/std/algorithms/alg.modifying.operations/alg.fill/fill_n.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.fill/fill_n.pass.cpp
index e774c91..77d8083 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.fill/fill_n.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.fill/fill_n.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 #if TEST_STD_VER > 17
 TEST_CONSTEXPR bool test_constexpr() {
diff --git a/test/std/algorithms/alg.modifying.operations/alg.generate/generate_n.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.generate/generate_n.pass.cpp
index 4ffdc64..82df626 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.generate/generate_n.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.generate/generate_n.pass.cpp
@@ -24,7 +24,7 @@
 #include <cassert>
 
 #include "test_iterators.h"
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 struct gen_test
 {
diff --git a/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp
index 6c74149..5622f55 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp
@@ -19,7 +19,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 struct is_odd {
   TEST_CONSTEXPR bool operator()(const int &i) const { return i & 1; }
diff --git a/test/std/algorithms/alg.modifying.operations/alg.remove/remove_if.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.remove/remove_if.pass.cpp
index 637a917..99f9adf 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.remove/remove_if.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.remove/remove_if.pass.cpp
@@ -21,7 +21,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 TEST_CONSTEXPR bool equal2 ( int i ) { return i == 2; }
 
diff --git a/test/std/algorithms/alg.nonmodifying/alg.search/search_n.pass.cpp b/test/std/algorithms/alg.nonmodifying/alg.search/search_n.pass.cpp
index 3c86127..228bc6b 100644
--- a/test/std/algorithms/alg.nonmodifying/alg.search/search_n.pass.cpp
+++ b/test/std/algorithms/alg.nonmodifying/alg.search/search_n.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 #if TEST_STD_VER > 17
 TEST_CONSTEXPR bool test_constexpr() {
diff --git a/test/std/algorithms/alg.nonmodifying/alg.search/search_n_pred.pass.cpp b/test/std/algorithms/alg.nonmodifying/alg.search/search_n_pred.pass.cpp
index 1356893..6a3ab75 100644
--- a/test/std/algorithms/alg.nonmodifying/alg.search/search_n_pred.pass.cpp
+++ b/test/std/algorithms/alg.nonmodifying/alg.search/search_n_pred.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "user_defined_integral.hpp"
+#include "user_defined_integral.h"
 
 #if TEST_STD_VER > 17
 TEST_CONSTEXPR bool eq(int a, int b) { return a == b; }
diff --git a/test/std/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp b/test/std/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp
index 15edec0..13a0d52 100644
--- a/test/std/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp
+++ b/test/std/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp
@@ -24,7 +24,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 #if TEST_STD_VER > 17
 TEST_CONSTEXPR bool eq(int a, int b) { return a == b; }
diff --git a/test/std/algorithms/alg.sorting/alg.heap.operations/make.heap/make_heap_comp.pass.cpp b/test/std/algorithms/alg.sorting/alg.heap.operations/make.heap/make_heap_comp.pass.cpp
index 23c501c..9aa3a22 100644
--- a/test/std/algorithms/alg.sorting/alg.heap.operations/make.heap/make_heap_comp.pass.cpp
+++ b/test/std/algorithms/alg.sorting/alg.heap.operations/make.heap/make_heap_comp.pass.cpp
@@ -20,7 +20,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 #include "test_iterators.h"
 
 struct indirect_less
diff --git a/test/std/algorithms/alg.sorting/alg.merge/inplace_merge_comp.pass.cpp b/test/std/algorithms/alg.sorting/alg.merge/inplace_merge_comp.pass.cpp
index 7ab5c0c..11cda44 100644
--- a/test/std/algorithms/alg.sorting/alg.merge/inplace_merge_comp.pass.cpp
+++ b/test/std/algorithms/alg.sorting/alg.merge/inplace_merge_comp.pass.cpp
@@ -56,7 +56,7 @@
 #endif  // TEST_STD_VER >= 11
 
 #include "test_iterators.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 std::mt19937 randomness;
 
diff --git a/test/std/algorithms/alg.sorting/alg.merge/merge_comp.pass.cpp b/test/std/algorithms/alg.sorting/alg.merge/merge_comp.pass.cpp
index 508a4f5..afa7073 100644
--- a/test/std/algorithms/alg.sorting/alg.merge/merge_comp.pass.cpp
+++ b/test/std/algorithms/alg.sorting/alg.merge/merge_comp.pass.cpp
@@ -26,7 +26,7 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 // #if TEST_STD_VER > 17
 // TEST_CONSTEXPR bool test_constexpr() {
diff --git a/test/std/algorithms/alg.sorting/alg.min.max/minmax_init_list_comp.pass.cpp b/test/std/algorithms/alg.sorting/alg.min.max/minmax_init_list_comp.pass.cpp
index efa0e92..5c919e5 100644
--- a/test/std/algorithms/alg.sorting/alg.min.max/minmax_init_list_comp.pass.cpp
+++ b/test/std/algorithms/alg.sorting/alg.min.max/minmax_init_list_comp.pass.cpp
@@ -21,7 +21,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 bool all_equal(int, int) { return false; } // everything is equal
 
diff --git a/test/std/containers/associative/map/map.access/index_key.pass.cpp b/test/std/containers/associative/map/map.access/index_key.pass.cpp
index 8df052e..eaa8e1d 100644
--- a/test/std/containers/associative/map/map.access/index_key.pass.cpp
+++ b/test/std/containers/associative/map/map.access/index_key.pass.cpp
@@ -16,9 +16,9 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #if TEST_STD_VER >= 11
 #include "container_test_types.h"
 #endif
diff --git a/test/std/containers/associative/map/map.access/index_rv_key.pass.cpp b/test/std/containers/associative/map/map.access/index_rv_key.pass.cpp
index 7effa0c..22ddaa2 100644
--- a/test/std/containers/associative/map/map.access/index_rv_key.pass.cpp
+++ b/test/std/containers/associative/map/map.access/index_rv_key.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "MoveOnly.h"
 #include "min_allocator.h"
 #include "container_test_types.h"
diff --git a/test/std/containers/associative/map/map.ops/count.pass.cpp b/test/std/containers/associative/map/map.ops/count.pass.cpp
index 8abae28..138c5fd 100644
--- a/test/std/containers/associative/map/map.ops/count.pass.cpp
+++ b/test/std/containers/associative/map/map.ops/count.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/map/map.ops/count_transparent.pass.cpp b/test/std/containers/associative/map/map.ops/count_transparent.pass.cpp
index fa64902..666a2b4 100644
--- a/test/std/containers/associative/map/map.ops/count_transparent.pass.cpp
+++ b/test/std/containers/associative/map/map.ops/count_transparent.pass.cpp
@@ -20,7 +20,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/map/map.ops/equal_range.pass.cpp b/test/std/containers/associative/map/map.ops/equal_range.pass.cpp
index c46e52c..76e9165 100644
--- a/test/std/containers/associative/map/map.ops/equal_range.pass.cpp
+++ b/test/std/containers/associative/map/map.ops/equal_range.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/map/map.ops/equal_range_transparent.pass.cpp b/test/std/containers/associative/map/map.ops/equal_range_transparent.pass.cpp
index 4422135..ad34383 100644
--- a/test/std/containers/associative/map/map.ops/equal_range_transparent.pass.cpp
+++ b/test/std/containers/associative/map/map.ops/equal_range_transparent.pass.cpp
@@ -23,7 +23,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/map/map.ops/find.pass.cpp b/test/std/containers/associative/map/map.ops/find.pass.cpp
index bcf498e..909e932 100644
--- a/test/std/containers/associative/map/map.ops/find.pass.cpp
+++ b/test/std/containers/associative/map/map.ops/find.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/map/map.ops/lower_bound.pass.cpp b/test/std/containers/associative/map/map.ops/lower_bound.pass.cpp
index 5b1c925..29688ba 100644
--- a/test/std/containers/associative/map/map.ops/lower_bound.pass.cpp
+++ b/test/std/containers/associative/map/map.ops/lower_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/map/map.ops/upper_bound.pass.cpp b/test/std/containers/associative/map/map.ops/upper_bound.pass.cpp
index c7fdd87..68e75b6 100644
--- a/test/std/containers/associative/map/map.ops/upper_bound.pass.cpp
+++ b/test/std/containers/associative/map/map.ops/upper_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/multimap/multimap.ops/count.pass.cpp b/test/std/containers/associative/multimap/multimap.ops/count.pass.cpp
index 053a771..40b855b 100644
--- a/test/std/containers/associative/multimap/multimap.ops/count.pass.cpp
+++ b/test/std/containers/associative/multimap/multimap.ops/count.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/multimap/multimap.ops/count_transparent.pass.cpp b/test/std/containers/associative/multimap/multimap.ops/count_transparent.pass.cpp
index e6348cb..18d3225 100644
--- a/test/std/containers/associative/multimap/multimap.ops/count_transparent.pass.cpp
+++ b/test/std/containers/associative/multimap/multimap.ops/count_transparent.pass.cpp
@@ -20,7 +20,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/multimap/multimap.ops/equal_range.pass.cpp b/test/std/containers/associative/multimap/multimap.ops/equal_range.pass.cpp
index 3d4997f..0aef2dd 100644
--- a/test/std/containers/associative/multimap/multimap.ops/equal_range.pass.cpp
+++ b/test/std/containers/associative/multimap/multimap.ops/equal_range.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/multimap/multimap.ops/equal_range_transparent.pass.cpp b/test/std/containers/associative/multimap/multimap.ops/equal_range_transparent.pass.cpp
index 95af97c..b2f1c33 100644
--- a/test/std/containers/associative/multimap/multimap.ops/equal_range_transparent.pass.cpp
+++ b/test/std/containers/associative/multimap/multimap.ops/equal_range_transparent.pass.cpp
@@ -23,7 +23,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/multimap/multimap.ops/find.pass.cpp b/test/std/containers/associative/multimap/multimap.ops/find.pass.cpp
index e526d9a..0680d5b 100644
--- a/test/std/containers/associative/multimap/multimap.ops/find.pass.cpp
+++ b/test/std/containers/associative/multimap/multimap.ops/find.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/multimap/multimap.ops/lower_bound.pass.cpp b/test/std/containers/associative/multimap/multimap.ops/lower_bound.pass.cpp
index 77550b5..5404c22 100644
--- a/test/std/containers/associative/multimap/multimap.ops/lower_bound.pass.cpp
+++ b/test/std/containers/associative/multimap/multimap.ops/lower_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/multimap/multimap.ops/upper_bound.pass.cpp b/test/std/containers/associative/multimap/multimap.ops/upper_bound.pass.cpp
index 762387d..2bc16d4 100644
--- a/test/std/containers/associative/multimap/multimap.ops/upper_bound.pass.cpp
+++ b/test/std/containers/associative/multimap/multimap.ops/upper_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "is_transparent.h"
 
 int main(int, char**)
diff --git a/test/std/containers/associative/multiset/count.pass.cpp b/test/std/containers/associative/multiset/count.pass.cpp
index 3ac6f94..21575fc 100644
--- a/test/std/containers/associative/multiset/count.pass.cpp
+++ b/test/std/containers/associative/multiset/count.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/multiset/count_transparent.pass.cpp b/test/std/containers/associative/multiset/count_transparent.pass.cpp
index 1239286..d686663 100644
--- a/test/std/containers/associative/multiset/count_transparent.pass.cpp
+++ b/test/std/containers/associative/multiset/count_transparent.pass.cpp
@@ -22,7 +22,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/multiset/equal_range.pass.cpp b/test/std/containers/associative/multiset/equal_range.pass.cpp
index 44c6c17..e32fc0a 100644
--- a/test/std/containers/associative/multiset/equal_range.pass.cpp
+++ b/test/std/containers/associative/multiset/equal_range.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/multiset/equal_range_transparent.pass.cpp b/test/std/containers/associative/multiset/equal_range_transparent.pass.cpp
index d052cf1..7e9c261 100644
--- a/test/std/containers/associative/multiset/equal_range_transparent.pass.cpp
+++ b/test/std/containers/associative/multiset/equal_range_transparent.pass.cpp
@@ -24,7 +24,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/multiset/find.pass.cpp b/test/std/containers/associative/multiset/find.pass.cpp
index 7a6584b..832e88f 100644
--- a/test/std/containers/associative/multiset/find.pass.cpp
+++ b/test/std/containers/associative/multiset/find.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/multiset/lower_bound.pass.cpp b/test/std/containers/associative/multiset/lower_bound.pass.cpp
index 6d31f04..9c776a3 100644
--- a/test/std/containers/associative/multiset/lower_bound.pass.cpp
+++ b/test/std/containers/associative/multiset/lower_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/multiset/upper_bound.pass.cpp b/test/std/containers/associative/multiset/upper_bound.pass.cpp
index 99a7e37..ebcd1eb 100644
--- a/test/std/containers/associative/multiset/upper_bound.pass.cpp
+++ b/test/std/containers/associative/multiset/upper_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/set/count.pass.cpp b/test/std/containers/associative/set/count.pass.cpp
index 8866aa7..06ddf78 100644
--- a/test/std/containers/associative/set/count.pass.cpp
+++ b/test/std/containers/associative/set/count.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/set/count_transparent.pass.cpp b/test/std/containers/associative/set/count_transparent.pass.cpp
index d94188d..b1b9bb1 100644
--- a/test/std/containers/associative/set/count_transparent.pass.cpp
+++ b/test/std/containers/associative/set/count_transparent.pass.cpp
@@ -22,7 +22,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/set/equal_range.pass.cpp b/test/std/containers/associative/set/equal_range.pass.cpp
index 5c43706..23c5269 100644
--- a/test/std/containers/associative/set/equal_range.pass.cpp
+++ b/test/std/containers/associative/set/equal_range.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/set/equal_range_transparent.pass.cpp b/test/std/containers/associative/set/equal_range_transparent.pass.cpp
index b69ff2d..1644a17 100644
--- a/test/std/containers/associative/set/equal_range_transparent.pass.cpp
+++ b/test/std/containers/associative/set/equal_range_transparent.pass.cpp
@@ -24,7 +24,7 @@
 #include <utility>
 
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 #include "test_macros.h"
 
 struct Comp {
diff --git a/test/std/containers/associative/set/find.pass.cpp b/test/std/containers/associative/set/find.pass.cpp
index cda1ea8..c32a333 100644
--- a/test/std/containers/associative/set/find.pass.cpp
+++ b/test/std/containers/associative/set/find.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/set/lower_bound.pass.cpp b/test/std/containers/associative/set/lower_bound.pass.cpp
index 9a25950..992e6e7 100644
--- a/test/std/containers/associative/set/lower_bound.pass.cpp
+++ b/test/std/containers/associative/set/lower_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/associative/set/upper_bound.pass.cpp b/test/std/containers/associative/set/upper_bound.pass.cpp
index 3649a5c..fc522b9 100644
--- a/test/std/containers/associative/set/upper_bound.pass.cpp
+++ b/test/std/containers/associative/set/upper_bound.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "private_constructor.hpp"
+#include "private_constructor.h"
 
 int main(int, char**)
 {
diff --git a/test/std/containers/map_allocator_requirement_test_templates.h b/test/std/containers/map_allocator_requirement_test_templates.h
index 64b4b60..7dc220f 100644
--- a/test/std/containers/map_allocator_requirement_test_templates.h
+++ b/test/std/containers/map_allocator_requirement_test_templates.h
@@ -23,7 +23,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "container_test_types.h"
 #include "assert_checkpoint.h"
 
diff --git a/test/std/containers/sequences/forwardlist/forwardlist.ops/remove_if.pass.cpp b/test/std/containers/sequences/forwardlist/forwardlist.ops/remove_if.pass.cpp
index a5cb138..589ae66 100644
--- a/test/std/containers/sequences/forwardlist/forwardlist.ops/remove_if.pass.cpp
+++ b/test/std/containers/sequences/forwardlist/forwardlist.ops/remove_if.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 
 template <class L, class Predicate>
diff --git a/test/std/containers/sequences/list/list.modifiers/insert_iter_iter_iter.pass.cpp b/test/std/containers/sequences/list/list.modifiers/insert_iter_iter_iter.pass.cpp
index 22ef0f7..708e57c 100644
--- a/test/std/containers/sequences/list/list.modifiers/insert_iter_iter_iter.pass.cpp
+++ b/test/std/containers/sequences/list/list.modifiers/insert_iter_iter_iter.pass.cpp
@@ -18,7 +18,7 @@
 #include "test_macros.h"
 #include "test_iterators.h"
 #include "min_allocator.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 template <class List>
 void test() {
diff --git a/test/std/containers/sequences/list/list.modifiers/insert_iter_size_value.pass.cpp b/test/std/containers/sequences/list/list.modifiers/insert_iter_size_value.pass.cpp
index f577fc0..2d20097 100644
--- a/test/std/containers/sequences/list/list.modifiers/insert_iter_size_value.pass.cpp
+++ b/test/std/containers/sequences/list/list.modifiers/insert_iter_size_value.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "min_allocator.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 template <class List>
diff --git a/test/std/containers/sequences/list/list.modifiers/insert_iter_value.pass.cpp b/test/std/containers/sequences/list/list.modifiers/insert_iter_value.pass.cpp
index 10a3d97..4b40512 100644
--- a/test/std/containers/sequences/list/list.modifiers/insert_iter_value.pass.cpp
+++ b/test/std/containers/sequences/list/list.modifiers/insert_iter_value.pass.cpp
@@ -16,7 +16,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 template <class List>
 void test()
diff --git a/test/std/containers/sequences/list/list.ops/remove_if.pass.cpp b/test/std/containers/sequences/list/list.ops/remove_if.pass.cpp
index 0944e68..be7ff85 100644
--- a/test/std/containers/sequences/list/list.ops/remove_if.pass.cpp
+++ b/test/std/containers/sequences/list/list.ops/remove_if.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 bool even(int i)
 {
diff --git a/test/std/containers/sequences/vector.bool/enabled_hash.pass.cpp b/test/std/containers/sequences/vector.bool/enabled_hash.pass.cpp
index 9ed0898..1da874b 100644
--- a/test/std/containers/sequences/vector.bool/enabled_hash.pass.cpp
+++ b/test/std/containers/sequences/vector.bool/enabled_hash.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <vector>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 #include "test_macros.h"
 #include "min_allocator.h"
 
diff --git a/test/std/containers/set_allocator_requirement_test_templates.h b/test/std/containers/set_allocator_requirement_test_templates.h
index 992b32b..5135a16 100644
--- a/test/std/containers/set_allocator_requirement_test_templates.h
+++ b/test/std/containers/set_allocator_requirement_test_templates.h
@@ -22,7 +22,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "container_test_types.h"
 #include "assert_checkpoint.h"
 
diff --git a/test/std/containers/unord/unord.map/unord.map.elem/index.pass.cpp b/test/std/containers/unord/unord.map/unord.map.elem/index.pass.cpp
index ff83f1d..9ca0edb 100644
--- a/test/std/containers/unord/unord.map/unord.map.elem/index.pass.cpp
+++ b/test/std/containers/unord/unord.map/unord.map.elem/index.pass.cpp
@@ -22,7 +22,7 @@
 #include "test_macros.h"
 #include "MoveOnly.h"
 #include "min_allocator.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 #if TEST_STD_VER >= 11
 #include "container_test_types.h"
diff --git a/test/std/diagnostics/syserr/syserr.hash/enabled_hash.pass.cpp b/test/std/diagnostics/syserr/syserr.hash/enabled_hash.pass.cpp
index 7d15103..bf5fb59 100644
--- a/test/std/diagnostics/syserr/syserr.hash/enabled_hash.pass.cpp
+++ b/test/std/diagnostics/syserr/syserr.hash/enabled_hash.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <system_error>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/default.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/default.pass.cpp
index 90efbf4..b71cebb 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/default.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/default.pass.cpp
@@ -18,7 +18,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/memory_resource_convert.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/memory_resource_convert.pass.cpp
index d0d33b3..f687367 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/memory_resource_convert.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.ctor/memory_resource_convert.pass.cpp
@@ -18,7 +18,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/equal.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/equal.pass.cpp
index 8b216e1..2d940e5 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/equal.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/equal.pass.cpp
@@ -21,7 +21,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/not_equal.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/not_equal.pass.cpp
index 803e9a0..459ec47 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/not_equal.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.eq/not_equal.pass.cpp
@@ -21,7 +21,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/allocate.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/allocate.pass.cpp
index af51ffc..46be069 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/allocate.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/allocate.pass.cpp
@@ -22,7 +22,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 namespace ex = std::experimental::pmr;
 
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair.pass.cpp
index de8a261..49cd870 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair.pass.cpp
@@ -21,7 +21,7 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "uses_alloc_types.hpp"
+#include "uses_alloc_types.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_const_lvalue_pair.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_const_lvalue_pair.pass.cpp
index 3b97ec3..62bd473 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_const_lvalue_pair.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_const_lvalue_pair.pass.cpp
@@ -23,9 +23,9 @@
 #include <cstdlib>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "test_memory_resource.h"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 #include "test_allocator.h"
 
 namespace ex = std::experimental::pmr;
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_rvalue.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_rvalue.pass.cpp
index 5e0597e..63416d8 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_rvalue.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_rvalue.pass.cpp
@@ -23,9 +23,9 @@
 #include <cstdlib>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "test_memory_resource.h"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 #include "test_allocator.h"
 
 namespace ex = std::experimental::pmr;
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_values.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_values.pass.cpp
index 1eaae06..3e89791 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_values.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_pair_values.pass.cpp
@@ -23,9 +23,9 @@
 #include <cstdlib>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "test_memory_resource.h"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 #include "test_allocator.h"
 
 namespace ex = std::experimental::pmr;
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp
index f75bd9e..fc946e0 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_piecewise_pair.pass.cpp
@@ -24,9 +24,9 @@
 #include <cstdlib>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "test_memory_resource.h"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 #include "test_allocator.h"
 
 namespace ex = std::experimental::pmr;
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_types.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_types.pass.cpp
index 0afc53b..f7bff71 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_types.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/construct_types.pass.cpp
@@ -21,9 +21,9 @@
 #include <cstdlib>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "test_memory_resource.h"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 #include "test_allocator.h"
 
 namespace ex = std::experimental::pmr;
diff --git a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/deallocate.pass.cpp b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/deallocate.pass.cpp
index 5677b86..b834e20 100644
--- a/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/deallocate.pass.cpp
+++ b/test/std/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/deallocate.pass.cpp
@@ -18,7 +18,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_copy.pass.cpp b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_copy.pass.cpp
index e8d9c77..c54ea47 100644
--- a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_copy.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_copy.pass.cpp
@@ -17,7 +17,7 @@
 #include <experimental/memory_resource>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_move.pass.cpp b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_move.pass.cpp
index 959ec44..28e4d4d 100644
--- a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_move.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/alloc_move.pass.cpp
@@ -17,7 +17,7 @@
 #include <experimental/memory_resource>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/default.pass.cpp b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/default.pass.cpp
index 2885a39..9b17412 100644
--- a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/default.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.ctor/default.pass.cpp
@@ -19,7 +19,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_allocate_and_deallocate.pass.cpp b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_allocate_and_deallocate.pass.cpp
index f88d6fc..6a8217d 100644
--- a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_allocate_and_deallocate.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_allocate_and_deallocate.pass.cpp
@@ -27,7 +27,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 namespace ex = std::experimental::pmr;
 
diff --git a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_is_equal.pass.cpp b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_is_equal.pass.cpp
index f987978..914fa1a 100644
--- a/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_is_equal.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/do_is_equal.pass.cpp
@@ -18,7 +18,7 @@
 #include <type_traits>
 #include <memory>
 #include <cassert>
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.aliases/header_string_synop.pass.cpp b/test/std/experimental/memory/memory.resource.aliases/header_string_synop.pass.cpp
index faf1f85..f482d84 100644
--- a/test/std/experimental/memory/memory.resource.aliases/header_string_synop.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.aliases/header_string_synop.pass.cpp
@@ -28,7 +28,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.global/default_resource.pass.cpp b/test/std/experimental/memory/memory.resource.global/default_resource.pass.cpp
index ac2726e..5aca44c 100644
--- a/test/std/experimental/memory/memory.resource.global/default_resource.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.global/default_resource.pass.cpp
@@ -31,7 +31,7 @@
 #include <experimental/memory_resource>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.global/new_delete_resource.pass.cpp b/test/std/experimental/memory/memory.resource.global/new_delete_resource.pass.cpp
index 9b9c505..788d74b 100644
--- a/test/std/experimental/memory/memory.resource.global/new_delete_resource.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.global/new_delete_resource.pass.cpp
@@ -16,7 +16,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource.global/null_memory_resource.pass.cpp b/test/std/experimental/memory/memory.resource.global/null_memory_resource.pass.cpp
index 5afbaf4..1d1884d 100644
--- a/test/std/experimental/memory/memory.resource.global/null_memory_resource.pass.cpp
+++ b/test/std/experimental/memory/memory.resource.global/null_memory_resource.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 namespace ex = std::experimental::pmr;
 
diff --git a/test/std/experimental/memory/memory.resource/memory.resource.eq/equal.pass.cpp b/test/std/experimental/memory/memory.resource/memory.resource.eq/equal.pass.cpp
index f9d4d5b..2d9a1af 100644
--- a/test/std/experimental/memory/memory.resource/memory.resource.eq/equal.pass.cpp
+++ b/test/std/experimental/memory/memory.resource/memory.resource.eq/equal.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 namespace ex = std::experimental::pmr;
 
diff --git a/test/std/experimental/memory/memory.resource/memory.resource.eq/not_equal.pass.cpp b/test/std/experimental/memory/memory.resource/memory.resource.eq/not_equal.pass.cpp
index 3f5e355..d757baa 100644
--- a/test/std/experimental/memory/memory.resource/memory.resource.eq/not_equal.pass.cpp
+++ b/test/std/experimental/memory/memory.resource/memory.resource.eq/not_equal.pass.cpp
@@ -16,7 +16,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource/memory.resource.public/allocate.pass.cpp b/test/std/experimental/memory/memory.resource/memory.resource.public/allocate.pass.cpp
index 38f4974..cc80fbe 100644
--- a/test/std/experimental/memory/memory.resource/memory.resource.public/allocate.pass.cpp
+++ b/test/std/experimental/memory/memory.resource/memory.resource.public/allocate.pass.cpp
@@ -27,7 +27,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 using std::experimental::pmr::memory_resource;
 
diff --git a/test/std/experimental/memory/memory.resource/memory.resource.public/deallocate.pass.cpp b/test/std/experimental/memory/memory.resource/memory.resource.public/deallocate.pass.cpp
index c315508..77ffb23 100644
--- a/test/std/experimental/memory/memory.resource/memory.resource.public/deallocate.pass.cpp
+++ b/test/std/experimental/memory/memory.resource/memory.resource.public/deallocate.pass.cpp
@@ -26,7 +26,7 @@
 #include <cstddef>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource/memory.resource.public/dtor.pass.cpp b/test/std/experimental/memory/memory.resource/memory.resource.public/dtor.pass.cpp
index b017c35..4759e83 100644
--- a/test/std/experimental/memory/memory.resource/memory.resource.public/dtor.pass.cpp
+++ b/test/std/experimental/memory/memory.resource/memory.resource.public/dtor.pass.cpp
@@ -22,7 +22,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/experimental/memory/memory.resource/memory.resource.public/is_equal.pass.cpp b/test/std/experimental/memory/memory.resource/memory.resource.public/is_equal.pass.cpp
index 9f66b8a..fd63171 100644
--- a/test/std/experimental/memory/memory.resource/memory.resource.public/is_equal.pass.cpp
+++ b/test/std/experimental/memory/memory.resource/memory.resource.public/is_equal.pass.cpp
@@ -24,7 +24,7 @@
 #include <experimental/memory_resource>
 #include <type_traits>
 #include <cassert>
-#include "test_memory_resource.hpp"
+#include "test_memory_resource.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy.pass.cpp
index 717c766..3183589 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy.pass.cpp
@@ -14,14 +14,14 @@
 
 // directory_entry(const directory_entry&) = default;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
-#include "test_convertible.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
+#include "test_convertible.h"
 
 TEST_SUITE(directory_entry_path_ctor_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy_assign.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy_assign.pass.cpp
index 4040933..11ee2fd 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy_assign.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/copy_assign.pass.cpp
@@ -17,13 +17,13 @@
 // void assign(path const&);
 // void replace_filename(path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 TEST_SUITE(directory_entry_ctor_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default.pass.cpp
index 5d28de3..0bc6703 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default.pass.cpp
@@ -14,7 +14,7 @@
 
 //          directory_entry() noexcept = default;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default_const.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default_const.pass.cpp
index 39fc521..75e6263 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default_const.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/default_const.pass.cpp
@@ -15,7 +15,7 @@
 
 //          directory_entry() noexcept = default;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move.pass.cpp
index f4c7e44..4e5b283 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move.pass.cpp
@@ -14,14 +14,14 @@
 
 // directory_entry(directory_entry&&) noexcept = default;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
-#include "test_convertible.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
+#include "test_convertible.h"
 
 TEST_SUITE(directory_entry_path_ctor_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move_assign.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move_assign.pass.cpp
index 38107da..9c85547 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move_assign.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/move_assign.pass.cpp
@@ -17,13 +17,13 @@
 // void assign(path const&);
 // void replace_filename(path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 TEST_SUITE(directory_entry_ctor_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/path.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/path.pass.cpp
index aac7f76..5188427 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/path.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.cons/path.pass.cpp
@@ -15,14 +15,14 @@
 // explicit directory_entry(const path);
 // directory_entry(const path&, error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
-#include "test_convertible.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
+#include "test_convertible.h"
 
 TEST_SUITE(directory_entry_path_ctor_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/assign.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/assign.pass.cpp
index b2240ed..0c5180b 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/assign.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/assign.pass.cpp
@@ -17,13 +17,13 @@
 // void assign(path const&);
 // void replace_filename(path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 TEST_SUITE(directory_entry_mods_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/refresh.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/refresh.pass.cpp
index 859763b..a9a01a5 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/refresh.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/refresh.pass.cpp
@@ -17,13 +17,13 @@
 // void assign(path const&);
 // void replace_filename(path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 TEST_SUITE(directory_entry_mods_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/replace_filename.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/replace_filename.pass.cpp
index e8ecdee..8ceb48b 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/replace_filename.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.mods/replace_filename.pass.cpp
@@ -17,13 +17,13 @@
 // void assign(path const&);
 // void replace_filename(path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 TEST_SUITE(directory_entry_mods_suite)
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/comparisons.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/comparisons.pass.cpp
index 2cac547..1633d9f 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/comparisons.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/comparisons.pass.cpp
@@ -20,7 +20,7 @@
 // bool operator>=(directory_entry const&) const noexcept;
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_size.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_size.pass.cpp
index 2d9d938..0ebbb29 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_size.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_size.pass.cpp
@@ -15,12 +15,12 @@
 // uintmax_t file_size() const;
 // uintmax_t file_size(error_code const&) const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
-#include "filesystem_test_helper.hpp"
-#include "rapid-cxx-test.hpp"
+#include "filesystem_test_helper.h"
+#include "rapid-cxx-test.h"
 
 #include <iostream>
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_type_obs.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_type_obs.pass.cpp
index 0a0c5ac..f5a44b7 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_type_obs.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/file_type_obs.pass.cpp
@@ -15,12 +15,12 @@
 // file_status status() const;
 // file_status status(error_code const&) const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
-#include "filesystem_test_helper.hpp"
-#include "rapid-cxx-test.hpp"
+#include "filesystem_test_helper.h"
+#include "rapid-cxx-test.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/hard_link_count.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/hard_link_count.pass.cpp
index 207eb6d..c7d30d1 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/hard_link_count.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/hard_link_count.pass.cpp
@@ -15,12 +15,12 @@
 // uintmax_t hard_link_count() const;
 // uintmax_t hard_link_count(error_code const&) const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
-#include "filesystem_test_helper.hpp"
-#include "rapid-cxx-test.hpp"
+#include "filesystem_test_helper.h"
+#include "rapid-cxx-test.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/last_write_time.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/last_write_time.pass.cpp
index 5da5528..fd6c81c 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/last_write_time.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/last_write_time.pass.cpp
@@ -15,12 +15,12 @@
 // file_time_type last_write_time() const;
 // file_time_type last_write_time(error_code const&) const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
-#include "filesystem_test_helper.hpp"
-#include "rapid-cxx-test.hpp"
+#include "filesystem_test_helper.h"
+#include "rapid-cxx-test.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/path.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/path.pass.cpp
index fea35d3..6f2a995 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/path.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/path.pass.cpp
@@ -15,7 +15,7 @@
 // const path& path() const noexcept;
 // operator const path&() const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/status.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/status.pass.cpp
index 2763c47..8ea1fdb 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/status.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/status.pass.cpp
@@ -15,12 +15,12 @@
 // file_status status() const;
 // file_status status(error_code const&) const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
-#include "filesystem_test_helper.hpp"
-#include "rapid-cxx-test.hpp"
+#include "filesystem_test_helper.h"
+#include "rapid-cxx-test.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/symlink_status.pass.cpp b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/symlink_status.pass.cpp
index bfa16fd..cff19bc 100644
--- a/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/symlink_status.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_entry/directory_entry.obs/symlink_status.pass.cpp
@@ -15,12 +15,12 @@
 // file_status symlink_status() const;
 // file_status symlink_status(error_code&) const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
-#include "filesystem_test_helper.hpp"
-#include "rapid-cxx-test.hpp"
+#include "filesystem_test_helper.h"
+#include "rapid-cxx-test.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy.pass.cpp
index 99da0c9..ca607ad 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy.pass.cpp
@@ -14,14 +14,14 @@
 
 // directory_iterator(directory_iterator const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy_assign.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy_assign.pass.cpp
index 6dd81f2..966501b 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy_assign.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/copy_assign.pass.cpp
@@ -14,14 +14,14 @@
 
 // directory_iterator& operator=(directory_iterator const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/ctor.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/ctor.pass.cpp
index 8cbea9d..325228a 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/ctor.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/ctor.pass.cpp
@@ -17,14 +17,14 @@
 // directory_iterator(const path& p, error_code& ec);
 // directory_iterator(const path& p, directory_options options, error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/default_ctor.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/default_ctor.pass.cpp
index 9f60ec2..6fdebb3 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/default_ctor.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/default_ctor.pass.cpp
@@ -15,7 +15,7 @@
 // directory_iterator::directory_iterator() noexcept
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/increment.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/increment.pass.cpp
index 71f7b2a..ca954e9 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/increment.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/increment.pass.cpp
@@ -15,14 +15,14 @@
 // directory_iterator& operator++();
 // directory_iterator& increment(error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 #include <iostream>
 
 using namespace fs;
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move.pass.cpp
index 7870d73..055b157 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move.pass.cpp
@@ -14,14 +14,14 @@
 
 // directory_iterator(directory_iterator&&) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move_assign.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move_assign.pass.cpp
index 2e41740..de76954 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move_assign.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.members/move_assign.pass.cpp
@@ -14,14 +14,14 @@
 
 // directory_iterator& operator=(directory_iterator const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 // The filesystem specification explicitly allows for self-move on
 // the directory iterators. Turn off this warning so we can test it.
diff --git a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.nonmembers/begin_end.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.nonmembers/begin_end.pass.cpp
index 2fd6abe..3134452 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.nonmembers/begin_end.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/directory_iterator.nonmembers/begin_end.pass.cpp
@@ -15,14 +15,14 @@
 // directory_iterator begin(directory_iterator iter) noexcept;
 // directory_iterator end(directory_iterator iter) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 #include <iostream>
 
 using namespace fs;
diff --git a/test/std/input.output/filesystems/class.directory_iterator/types.pass.cpp b/test/std/input.output/filesystems/class.directory_iterator/types.pass.cpp
index 3932be0..9d9f923 100644
--- a/test/std/input.output/filesystems/class.directory_iterator/types.pass.cpp
+++ b/test/std/input.output/filesystems/class.directory_iterator/types.pass.cpp
@@ -18,7 +18,7 @@
 // typedef ... reference;
 // typedef ... iterator_category
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.file_status/file_status.cons.pass.cpp b/test/std/input.output/filesystems/class.file_status/file_status.cons.pass.cpp
index 6d5b9e6..aba2e66 100644
--- a/test/std/input.output/filesystems/class.file_status/file_status.cons.pass.cpp
+++ b/test/std/input.output/filesystems/class.file_status/file_status.cons.pass.cpp
@@ -15,11 +15,11 @@
 // explicit file_status() noexcept;
 // explicit file_status(file_type, perms prms = perms::unknown) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.file_status/file_status.mods.pass.cpp b/test/std/input.output/filesystems/class.file_status/file_status.mods.pass.cpp
index 3e7df00..9d00f31 100644
--- a/test/std/input.output/filesystems/class.file_status/file_status.mods.pass.cpp
+++ b/test/std/input.output/filesystems/class.file_status/file_status.mods.pass.cpp
@@ -15,7 +15,7 @@
 // void type(file_type) noexcept;
 // void permissions(perms) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.file_status/file_status.obs.pass.cpp b/test/std/input.output/filesystems/class.file_status/file_status.obs.pass.cpp
index 5583d84..6ab9c25 100644
--- a/test/std/input.output/filesystems/class.file_status/file_status.obs.pass.cpp
+++ b/test/std/input.output/filesystems/class.file_status/file_status.obs.pass.cpp
@@ -15,7 +15,7 @@
 // file_type type() const noexcept;
 // perms permissions(p) const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.filesystem_error/filesystem_error.members.pass.cpp b/test/std/input.output/filesystems/class.filesystem_error/filesystem_error.members.pass.cpp
index d9d1a03..85e09bb 100644
--- a/test/std/input.output/filesystems/class.filesystem_error/filesystem_error.members.pass.cpp
+++ b/test/std/input.output/filesystems/class.filesystem_error/filesystem_error.members.pass.cpp
@@ -20,7 +20,7 @@
 // const path& path1() const noexcept;
 // const path& path2() const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.path/path.itr/iterator.pass.cpp b/test/std/input.output/filesystems/class.path/path.itr/iterator.pass.cpp
index 558206d..07f57ef 100644
--- a/test/std/input.output/filesystems/class.path/path.itr/iterator.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.itr/iterator.pass.cpp
@@ -18,13 +18,13 @@
 //      path(InputIterator first, InputIterator last);
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <iterator>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp
index 2f468e5..9a9fade 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp
@@ -21,15 +21,15 @@
 //      path& append(InputIterator first, InputIterator last);
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <string_view>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 #include "verbose_assert.h"
 
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.assign/braced_init.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.assign/braced_init.pass.cpp
index aff89f2..11eb9e4 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.assign/braced_init.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.assign/braced_init.pass.cpp
@@ -14,12 +14,12 @@
 
 // path& operator=(path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 
 int main(int, char**) {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.assign/copy.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.assign/copy.pass.cpp
index 9265c70..878d219 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.assign/copy.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.assign/copy.pass.cpp
@@ -14,7 +14,7 @@
 
 // path& operator=(path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp
index 5e5fb1e..b845c87 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp
@@ -14,12 +14,12 @@
 
 // path& operator=(path&&) noexcept
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 
 int main(int, char**) {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.assign/source.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.assign/source.pass.cpp
index 9c23e3b..e7d79dc 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.assign/source.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.assign/source.pass.cpp
@@ -21,15 +21,15 @@
 //      path& assign(InputIterator first, InputIterator last);
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <string_view>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 #include <iostream>
 
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.compare.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.compare.pass.cpp
index 165e62f..3a9d1f5 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.compare.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.compare.pass.cpp
@@ -26,15 +26,15 @@
 // size_t hash_value(path const&) noexcept;
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <vector>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 #include "verbose_assert.h"
 
 struct PathCompareTest {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp
index b074e83..4bec0bf 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp
@@ -27,7 +27,7 @@
 //   path& concat(InputIterator first, InputIterator last);
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <string>
 #include <string_view>
@@ -35,8 +35,8 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 struct ConcatOperatorTestcase {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.construct/copy.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.construct/copy.pass.cpp
index 1490c0b..1260c66 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.construct/copy.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.construct/copy.pass.cpp
@@ -14,7 +14,7 @@
 
 // path(path const&)
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.construct/default.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.construct/default.pass.cpp
index b31728d..08461cc 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.construct/default.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.construct/default.pass.cpp
@@ -14,7 +14,7 @@
 
 // path() noexcept
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp
index 494a77c..a1a07fb 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp
@@ -14,12 +14,12 @@
 
 // path(path&&) noexcept
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 
 int main(int, char**) {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp
index bcb9986..fa68b5d 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp
@@ -18,14 +18,14 @@
 //      path(InputIterator first, InputIterator last);
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
 #include "min_allocator.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 
 template <class CharT, class ...Args>
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.decompose/empty.fail.cpp b/test/std/input.output/filesystems/class.path/path.member/path.decompose/empty.fail.cpp
index 5248f67..dbadf46 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.decompose/empty.fail.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.decompose/empty.fail.cpp
@@ -16,7 +16,7 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.decompose/path.decompose.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.decompose/path.decompose.pass.cpp
index be9cefb..4674dc1 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.decompose/path.decompose.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.decompose/path.decompose.pass.cpp
@@ -43,15 +43,15 @@
 // iterator end() const;
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <vector>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 #include "assert_checkpoint.h"
 #include "verbose_assert.h"
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_normal.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_normal.pass.cpp
index f1e6165..5d4e689 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_normal.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_normal.pass.cpp
@@ -14,7 +14,7 @@
 
 // path lexically_normal() const;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <vector>
 #include <iostream>
@@ -22,8 +22,8 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**) {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp
index 7e31956..0466b8a 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp
@@ -15,7 +15,7 @@
 // path lexically_relative(const path& p) const;
 // path lexically_proximate(const path& p) const;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <vector>
 #include <iostream>
@@ -23,8 +23,8 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**) {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/generic_string_alloc.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/generic_string_alloc.pass.cpp
index 707a701..d6082cb 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/generic_string_alloc.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/generic_string_alloc.pass.cpp
@@ -17,15 +17,15 @@
 // basic_string<ECharT, Traits, Allocator>
 // generic_string(const Allocator& a = Allocator()) const;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "min_allocator.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 MultiStringType longString = MKSTR("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/123456789/abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp
index 04ae673..454833d 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.generic.obs/named_overloads.pass.cpp
@@ -19,15 +19,15 @@
 // std::u32string generic_u32string() const;
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "min_allocator.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 MultiStringType longString = MKSTR("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/123456789/abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/clear.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/clear.pass.cpp
index 0153853..b20abd4 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/clear.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/clear.pass.cpp
@@ -14,14 +14,14 @@
 
 // void clear() noexcept
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**) {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/make_preferred.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/make_preferred.pass.cpp
index 4530ef8..aeb2028 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/make_preferred.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/make_preferred.pass.cpp
@@ -14,14 +14,14 @@
 
 // path& make_preferred()
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 struct MakePreferredTestcase {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/remove_filename.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/remove_filename.pass.cpp
index 7cb562c..a000dcc 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/remove_filename.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/remove_filename.pass.cpp
@@ -14,14 +14,14 @@
 
 // path& remove_filename()
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 #include "verbose_assert.h"
 
 struct RemoveFilenameTestcase {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_extension.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_extension.pass.cpp
index 6fec420..69b3dbd 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_extension.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_extension.pass.cpp
@@ -14,14 +14,14 @@
 
 // path& replace_extension(path const& p = path())
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 struct ReplaceExtensionTestcase {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_filename.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_filename.pass.cpp
index 8142e79..2369cc6 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_filename.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/replace_filename.pass.cpp
@@ -14,14 +14,14 @@
 
 // path& replace_filename()
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 #include "assert_checkpoint.h"
 #include "verbose_assert.h"
 
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/swap.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/swap.pass.cpp
index 2e9dac5..3b9e255 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.modifiers/swap.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.modifiers/swap.pass.cpp
@@ -14,14 +14,14 @@
 
 // void swap(path& rhs) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 struct SwapTestcase {
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/c_str.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/c_str.pass.cpp
index 8b35ee8..3b8ac09 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/c_str.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/c_str.pass.cpp
@@ -15,12 +15,12 @@
 
 // const value_type* c_str() const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**)
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp
index c06de97..4ab101c 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/named_overloads.pass.cpp
@@ -19,15 +19,15 @@
 // std::u32string u32string() const;
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "min_allocator.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 
 MultiStringType longString = MKSTR("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/123456789/abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/native.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/native.pass.cpp
index 3b88b5d..e802a06 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/native.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/native.pass.cpp
@@ -14,12 +14,12 @@
 
 // const string_type& native() const noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**)
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/operator_string.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/operator_string.pass.cpp
index 9f00690..292a61b 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/operator_string.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/operator_string.pass.cpp
@@ -15,12 +15,12 @@
 
 // operator string_type() const;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**)
diff --git a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/string_alloc.pass.cpp b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/string_alloc.pass.cpp
index 4ace380..c1a7c42 100644
--- a/test/std/input.output/filesystems/class.path/path.member/path.native.obs/string_alloc.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.member/path.native.obs/string_alloc.pass.cpp
@@ -17,15 +17,15 @@
 // basic_string<ECharT, Traits, Allocator>
 // string(const Allocator& a = Allocator()) const;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "min_allocator.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 
 // the SSO is always triggered for strings of size 2.
diff --git a/test/std/input.output/filesystems/class.path/path.nonmember/append_op.fail.cpp b/test/std/input.output/filesystems/class.path/path.nonmember/append_op.fail.cpp
index bcc4758..e326c17 100644
--- a/test/std/input.output/filesystems/class.path/path.nonmember/append_op.fail.cpp
+++ b/test/std/input.output/filesystems/class.path/path.nonmember/append_op.fail.cpp
@@ -10,7 +10,7 @@
 
 // <filesystem>
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 using namespace fs;
 
@@ -25,4 +25,4 @@
   (void)(LHS / RHS); // expected-error {{invalid operands to binary expression}}
 
   return 0;
-}
\ No newline at end of file
+}
diff --git a/test/std/input.output/filesystems/class.path/path.nonmember/append_op.pass.cpp b/test/std/input.output/filesystems/class.path/path.nonmember/append_op.pass.cpp
index 67af376..ea36fb1 100644
--- a/test/std/input.output/filesystems/class.path/path.nonmember/append_op.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.nonmember/append_op.pass.cpp
@@ -12,12 +12,12 @@
 
 // path operator/(path const&, path const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "filesystem_test_helper.hpp"
+#include "filesystem_test_helper.h"
 
 // This is mainly tested via the member append functions.
 int main(int, char**)
diff --git a/test/std/input.output/filesystems/class.path/path.nonmember/comparison_ops.fail.cpp b/test/std/input.output/filesystems/class.path/path.nonmember/comparison_ops.fail.cpp
index 8f17321..1e73ad3 100644
--- a/test/std/input.output/filesystems/class.path/path.nonmember/comparison_ops.fail.cpp
+++ b/test/std/input.output/filesystems/class.path/path.nonmember/comparison_ops.fail.cpp
@@ -11,7 +11,7 @@
 // <filesystem>
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 using namespace fs;
 
@@ -31,4 +31,4 @@
   (void)(LHS >= RHS); // expected-error {{invalid operands to binary expression}}
 
   return 0;
-}
\ No newline at end of file
+}
diff --git a/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp b/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp
index 557849c..90bf1c9 100644
--- a/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.nonmember/path.factory.pass.cpp
@@ -15,14 +15,14 @@
 // template <class InputIter>
 //   path u8path(InputIter, InputIter);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**)
diff --git a/test/std/input.output/filesystems/class.path/path.nonmember/path.io.pass.cpp b/test/std/input.output/filesystems/class.path/path.nonmember/path.io.pass.cpp
index 31eea92..a5ec959 100644
--- a/test/std/input.output/filesystems/class.path/path.nonmember/path.io.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.nonmember/path.io.pass.cpp
@@ -21,7 +21,7 @@
 // operator>>(basic_istream<charT, traits>& is, path& p)
 //
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <sstream>
 #include <cassert>
@@ -29,8 +29,8 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 MultiStringType InStr =  MKSTR("abcdefg/\"hijklmnop\"/qrstuvwxyz/123456789");
 MultiStringType OutStr = MKSTR("\"abcdefg/\\\"hijklmnop\\\"/qrstuvwxyz/123456789\"");
diff --git a/test/std/input.output/filesystems/class.path/path.nonmember/path.io.unicode_bug.pass.cpp b/test/std/input.output/filesystems/class.path/path.nonmember/path.io.unicode_bug.pass.cpp
index c5bb6bf..fb2fd46 100644
--- a/test/std/input.output/filesystems/class.path/path.nonmember/path.io.unicode_bug.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.nonmember/path.io.unicode_bug.pass.cpp
@@ -26,15 +26,15 @@
 // passes.
 // XFAIL: *
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <sstream>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 MultiStringType InStr =  MKSTR("abcdefg/\"hijklmnop\"/qrstuvwxyz/123456789");
 MultiStringType OutStr = MKSTR("\"abcdefg/\\\"hijklmnop\\\"/qrstuvwxyz/123456789\"");
diff --git a/test/std/input.output/filesystems/class.path/path.nonmember/swap.pass.cpp b/test/std/input.output/filesystems/class.path/path.nonmember/swap.pass.cpp
index 51bb03e..c327ed2 100644
--- a/test/std/input.output/filesystems/class.path/path.nonmember/swap.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/path.nonmember/swap.pass.cpp
@@ -12,13 +12,13 @@
 
 // void swap(path& lhs, path& rhs) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 // NOTE: this is tested in path.members/path.modifiers via the member swap.
diff --git a/test/std/input.output/filesystems/class.path/synop.pass.cpp b/test/std/input.output/filesystems/class.path/synop.pass.cpp
index 8aa186e..a47ab25 100644
--- a/test/std/input.output/filesystems/class.path/synop.pass.cpp
+++ b/test/std/input.output/filesystems/class.path/synop.pass.cpp
@@ -16,7 +16,7 @@
 // typedef basic_string<value_type> string_type;
 // static constexpr value_type preferred_separator = ...;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy.pass.cpp
index 9179908..695ac37 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy.pass.cpp
@@ -14,14 +14,14 @@
 
 // recursive_recursive_directory_iterator(recursive_recursive_directory_iterator const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy_assign.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy_assign.pass.cpp
index de97832..2fcebe9 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy_assign.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/copy_assign.pass.cpp
@@ -14,14 +14,14 @@
 
 // recursive_directory_iterator& operator=(recursive_directory_iterator const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/ctor.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/ctor.pass.cpp
index 114285e..538f547 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/ctor.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/ctor.pass.cpp
@@ -19,14 +19,14 @@
 // recursive_directory_iterator(const path& p, directory_options options, error_code& ec);
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/depth.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/depth.pass.cpp
index 47b344a..23adbbe 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/depth.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/depth.pass.cpp
@@ -14,14 +14,14 @@
 
 // int depth() const
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/disable_recursion_pending.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/disable_recursion_pending.pass.cpp
index a24559c..eb5e63f 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/disable_recursion_pending.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/disable_recursion_pending.pass.cpp
@@ -14,14 +14,14 @@
 
 // void disable_recursion_pending();
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/increment.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/increment.pass.cpp
index ea9f4de..799cedf 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/increment.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/increment.pass.cpp
@@ -15,14 +15,14 @@
 // recursive_directory_iterator& operator++();
 // recursive_directory_iterator& increment(error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move.pass.cpp
index c203106..316f8e6 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move.pass.cpp
@@ -14,14 +14,14 @@
 
 // recursive_directory_iterator(recursive_directory_iterator&&) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move_assign.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move_assign.pass.cpp
index 7a41ada..b8dd116 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move_assign.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/move_assign.pass.cpp
@@ -14,14 +14,14 @@
 
 // recursive_directory_iterator& operator=(recursive_directory_iterator const&);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 // The filesystem specification explicitly allows for self-move on
 // the directory iterators. Turn off this warning so we can test it.
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/pop.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/pop.pass.cpp
index 2cf3638..55325e2 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/pop.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/pop.pass.cpp
@@ -15,13 +15,13 @@
 // void pop();
 // void pop(error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/recursion_pending.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/recursion_pending.pass.cpp
index 1ffe664..120491a 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/recursion_pending.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.members/recursion_pending.pass.cpp
@@ -14,14 +14,14 @@
 
 // bool recursion_pending() const;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.nonmembers/begin_end.pass.cpp b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.nonmembers/begin_end.pass.cpp
index 91f2071..f1869ac 100644
--- a/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.nonmembers/begin_end.pass.cpp
+++ b/test/std/input.output/filesystems/class.rec.dir.itr/rec.dir.itr.nonmembers/begin_end.pass.cpp
@@ -15,14 +15,14 @@
 // recursive_directory_iterator begin(recursive_directory_iterator iter) noexcept;
 // recursive_directory_iterator end(recursive_directory_iterator iter) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <set>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 #include <iostream>
 
 using namespace fs;
diff --git a/test/std/input.output/filesystems/fs.enum/enum.copy_options.pass.cpp b/test/std/input.output/filesystems/fs.enum/enum.copy_options.pass.cpp
index b949960..7bc129f 100644
--- a/test/std/input.output/filesystems/fs.enum/enum.copy_options.pass.cpp
+++ b/test/std/input.output/filesystems/fs.enum/enum.copy_options.pass.cpp
@@ -12,7 +12,7 @@
 
 // enum class copy_options;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/fs.enum/enum.directory_options.pass.cpp b/test/std/input.output/filesystems/fs.enum/enum.directory_options.pass.cpp
index 43b0945..44e1c63 100644
--- a/test/std/input.output/filesystems/fs.enum/enum.directory_options.pass.cpp
+++ b/test/std/input.output/filesystems/fs.enum/enum.directory_options.pass.cpp
@@ -12,7 +12,7 @@
 
 // enum class directory_options;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 #include <sys/stat.h>
diff --git a/test/std/input.output/filesystems/fs.enum/enum.file_type.pass.cpp b/test/std/input.output/filesystems/fs.enum/enum.file_type.pass.cpp
index c1f1607..097b41c 100644
--- a/test/std/input.output/filesystems/fs.enum/enum.file_type.pass.cpp
+++ b/test/std/input.output/filesystems/fs.enum/enum.file_type.pass.cpp
@@ -12,7 +12,7 @@
 
 // enum class file_type;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp b/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp
index d60225d..b00a935 100644
--- a/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp
+++ b/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp
@@ -13,7 +13,7 @@
 // class path;
 // enum class format;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
diff --git a/test/std/input.output/filesystems/fs.enum/enum.perm_options.pass.cpp b/test/std/input.output/filesystems/fs.enum/enum.perm_options.pass.cpp
index 1fd353d..41fb731 100644
--- a/test/std/input.output/filesystems/fs.enum/enum.perm_options.pass.cpp
+++ b/test/std/input.output/filesystems/fs.enum/enum.perm_options.pass.cpp
@@ -12,7 +12,7 @@
 
 // enum class perm_options;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 #include <sys/stat.h>
diff --git a/test/std/input.output/filesystems/fs.enum/enum.perms.pass.cpp b/test/std/input.output/filesystems/fs.enum/enum.perms.pass.cpp
index 93b5278..a9613f2 100644
--- a/test/std/input.output/filesystems/fs.enum/enum.perms.pass.cpp
+++ b/test/std/input.output/filesystems/fs.enum/enum.perms.pass.cpp
@@ -12,7 +12,7 @@
 
 // enum class perms;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 #include <sys/stat.h>
diff --git a/test/std/input.output/filesystems/fs.filesystem.synopsis/file_time_type.pass.cpp b/test/std/input.output/filesystems/fs.filesystem.synopsis/file_time_type.pass.cpp
index e88ef1d..b16f860 100644
--- a/test/std/input.output/filesystems/fs.filesystem.synopsis/file_time_type.pass.cpp
+++ b/test/std/input.output/filesystems/fs.filesystem.synopsis/file_time_type.pass.cpp
@@ -12,7 +12,7 @@
 
 // typedef TrivialClock file_time_type;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <chrono>
 #include <type_traits>
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.absolute/absolute.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.absolute/absolute.pass.cpp
index 2f06fd1..c2b6466 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.absolute/absolute.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.absolute/absolute.pass.cpp
@@ -12,13 +12,13 @@
 
 // path absolute(const path& p, const path& base=current_path());
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.canonical/canonical.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.canonical/canonical.pass.cpp
index 7717c26..9009e7d 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.canonical/canonical.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.canonical/canonical.pass.cpp
@@ -13,13 +13,13 @@
 // path canonical(const path& p);
 // path canonical(const path& p, error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy/copy.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy/copy.pass.cpp
index c791a74..8256543 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy/copy.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy/copy.pass.cpp
@@ -16,14 +16,14 @@
 // void copy(const path& from, const path& to, copy_options options,
 //           error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cstddef>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file.pass.cpp
index 90da3b5..5dd29f5 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file.pass.cpp
@@ -16,14 +16,14 @@
 // bool copy_file(const path& from, const path& to, copy_options options,
 //           error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <chrono>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 #include <iostream>
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file_large.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file_large.pass.cpp
index f419039..24a3369 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file_large.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file_large.pass.cpp
@@ -17,14 +17,14 @@
 // bool copy_file(const path& from, const path& to, copy_options options,
 //           error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <chrono>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_symlink/copy_symlink.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_symlink/copy_symlink.pass.cpp
index e687ee5..676e04b 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_symlink/copy_symlink.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_symlink/copy_symlink.pass.cpp
@@ -14,13 +14,13 @@
 // void copy_symlink(const path& existing_symlink, const path& new_symlink,
 //                   error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directories/create_directories.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directories/create_directories.pass.cpp
index c7a7203..1a7deef 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directories/create_directories.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directories/create_directories.pass.cpp
@@ -13,13 +13,13 @@
 // bool create_directories(const path& p);
 // bool create_directories(const path& p, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory.pass.cpp
index f512a30..e5e21fa 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory.pass.cpp
@@ -15,13 +15,13 @@
 // bool create_directory(const path& p, const path& attr);
 // bool create_directory(const path& p, const path& attr, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory_with_attributes.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory_with_attributes.pass.cpp
index 796b7a7..248c8bd 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory_with_attributes.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory_with_attributes.pass.cpp
@@ -13,13 +13,13 @@
 // bool create_directory(const path& p, const path& attr);
 // bool create_directory(const path& p, const path& attr, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory_symlink/create_directory_symlink.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory_symlink/create_directory_symlink.pass.cpp
index e4bf090..3dc6291 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory_symlink/create_directory_symlink.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory_symlink/create_directory_symlink.pass.cpp
@@ -14,12 +14,12 @@
 // void create_directory_symlink(const path& existing_symlink, const path& new_symlink,
 //                   error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_hard_link/create_hard_link.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_hard_link/create_hard_link.pass.cpp
index b645ccb..2f4da65 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_hard_link/create_hard_link.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_hard_link/create_hard_link.pass.cpp
@@ -14,11 +14,11 @@
 // void create_hard_link(const path& existing_symlink, const path& new_symlink,
 //                   error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_symlink/create_symlink.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_symlink/create_symlink.pass.cpp
index a2658a5..c079ab3 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_symlink/create_symlink.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_symlink/create_symlink.pass.cpp
@@ -14,12 +14,12 @@
 // void create_symlink(const path& existing_symlink, const path& new_symlink,
 //                   error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.current_path/current_path.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.current_path/current_path.pass.cpp
index 41136a7..cb2d0d6 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.current_path/current_path.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.current_path/current_path.pass.cpp
@@ -15,13 +15,13 @@
 // void current_path(path const&);
 // void current_path(path const&, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.equivalent/equivalent.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.equivalent/equivalent.pass.cpp
index ebe4fc6..382e9bb 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.equivalent/equivalent.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.equivalent/equivalent.pass.cpp
@@ -13,13 +13,13 @@
 // bool equivalent(path const& lhs, path const& rhs);
 // bool equivalent(path const& lhs, path const& rhs, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.exists/exists.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.exists/exists.pass.cpp
index 2ae1c41..45270d4 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.exists/exists.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.exists/exists.pass.cpp
@@ -14,13 +14,13 @@
 // bool exists(path const& p);
 // bool exists(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.file_size/file_size.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.file_size/file_size.pass.cpp
index 3d597b0..200358d 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.file_size/file_size.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.file_size/file_size.pass.cpp
@@ -13,13 +13,13 @@
 // uintmax_t file_size(const path& p);
 // uintmax_t file_size(const path& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.hard_lk_ct/hard_link_count.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.hard_lk_ct/hard_link_count.pass.cpp
index 55527c9..7a204ed 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.hard_lk_ct/hard_link_count.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.hard_lk_ct/hard_link_count.pass.cpp
@@ -13,13 +13,13 @@
 // uintmax_t hard_link_count(const path& p);
 // uintmax_t hard_link_count(const path& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_block_file/is_block_file.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_block_file/is_block_file.pass.cpp
index fbfb62c..6cfbc34 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_block_file/is_block_file.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_block_file/is_block_file.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_block_file(path const& p);
 // bool is_block_file(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_char_file/is_character_file.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_char_file/is_character_file.pass.cpp
index e011dce..12e6601 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_char_file/is_character_file.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_char_file/is_character_file.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_character_file(path const& p);
 // bool is_character_file(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_directory/is_directory.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_directory/is_directory.pass.cpp
index 0491298..73dc538 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_directory/is_directory.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_directory/is_directory.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_directory(path const& p);
 // bool is_directory(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_empty/is_empty.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_empty/is_empty.pass.cpp
index 8a8fc50..affc77f 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_empty/is_empty.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_empty/is_empty.pass.cpp
@@ -13,13 +13,13 @@
 // bool is_empty(path const& p);
 // bool is_empty(path const& p, std::error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_fifo/is_fifo.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_fifo/is_fifo.pass.cpp
index 8cf036d..4dcf043 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_fifo/is_fifo.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_fifo/is_fifo.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_fifo(path const& p);
 // bool is_fifo(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_other/is_other.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_other/is_other.pass.cpp
index fb71070..894cc57 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_other/is_other.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_other/is_other.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_other(path const& p);
 // bool is_other(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_regular_file/is_regular_file.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_regular_file/is_regular_file.pass.cpp
index 55d97f2..3fcf779 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_regular_file/is_regular_file.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_regular_file/is_regular_file.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_regular_file(path const& p);
 // bool is_regular_file(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_socket/is_socket.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_socket/is_socket.pass.cpp
index f0d894c..ba727d6 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_socket/is_socket.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_socket/is_socket.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_socket(path const& p);
 // bool is_socket(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_symlink/is_symlink.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_symlink/is_symlink.pass.cpp
index 8d17235..97b6142 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_symlink/is_symlink.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.is_symlink/is_symlink.pass.cpp
@@ -14,13 +14,13 @@
 // bool is_symlink(path const& p);
 // bool is_symlink(path const& p, std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp
index 5e26e8e..a66d4bf 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp
@@ -16,15 +16,15 @@
 // void last_write_time(const path& p, file_time_type new_type,
 //                      std::error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <chrono>
 #include <fstream>
 #include <cstdlib>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 #include <sys/stat.h>
 #include <iostream>
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.permissions/permissions.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.permissions/permissions.pass.cpp
index 434fcea..d3090f5 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.permissions/permissions.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.permissions/permissions.pass.cpp
@@ -17,11 +17,11 @@
 
 
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.proximate/proximate.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.proximate/proximate.pass.cpp
index a7c4984..a908d4c 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.proximate/proximate.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.proximate/proximate.pass.cpp
@@ -14,7 +14,7 @@
 // path proximate(const path& p, const path& base = current_path())
 // path proximate(const path& p, const path& base, error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <vector>
 #include <iostream>
@@ -22,9 +22,9 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 
 static int count_path_elems(const fs::path& p) {
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.read_symlink/read_symlink.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.read_symlink/read_symlink.pass.cpp
index 488738e..4c53280 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.read_symlink/read_symlink.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.read_symlink/read_symlink.pass.cpp
@@ -13,11 +13,11 @@
 // path read_symlink(const path& p);
 // path read_symlink(const path& p, error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.relative/relative.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.relative/relative.pass.cpp
index fd9bac7..dda88f0 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.relative/relative.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.relative/relative.pass.cpp
@@ -14,16 +14,16 @@
 // path proximate(const path& p, const path& base = current_path())
 // path proximate(const path& p, const path& base, error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <string>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 
 TEST_SUITE(filesystem_proximate_path_test_suite)
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove/remove.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove/remove.pass.cpp
index 3fb2052..0bb7d25 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove/remove.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove/remove.pass.cpp
@@ -13,11 +13,11 @@
 // bool remove(const path& p);
 // bool remove(const path& p, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove_all/remove_all.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove_all/remove_all.pass.cpp
index 523ce5f..de685b9 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove_all/remove_all.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.remove_all/remove_all.pass.cpp
@@ -13,11 +13,11 @@
 // uintmax_t remove_all(const path& p);
 // uintmax_t remove_all(const path& p, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.rename/rename.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.rename/rename.pass.cpp
index 8373d67..85eafc3 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.rename/rename.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.rename/rename.pass.cpp
@@ -13,11 +13,11 @@
 // void rename(const path& old_p, const path& new_p);
 // void rename(const path& old_p,  const path& new_p, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.resize_file/resize_file.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.resize_file/resize_file.pass.cpp
index 43ce5b0..1f58331 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.resize_file/resize_file.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.resize_file/resize_file.pass.cpp
@@ -13,11 +13,11 @@
 // void resize_file(const path& p, uintmax_t new_size);
 // void resize_file(const path& p, uintmax_t new_size, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.space/space.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.space/space.pass.cpp
index 7bb6c55..f92f21a 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.space/space.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.space/space.pass.cpp
@@ -13,12 +13,12 @@
 // space_info space(const path& p);
 // space_info space(const path& p, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <sys/statvfs.h>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.status/status.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.status/status.pass.cpp
index 93444bb..2c7c673 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.status/status.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.status/status.pass.cpp
@@ -13,11 +13,11 @@
 // file_status status(const path& p);
 // file_status status(const path& p, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.status_known/status_known.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.status_known/status_known.pass.cpp
index 93a251c..abde19e 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.status_known/status_known.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.status_known/status_known.pass.cpp
@@ -12,13 +12,13 @@
 
 // bool status_known(file_status s) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.symlink_status/symlink_status.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.symlink_status/symlink_status.pass.cpp
index a4d883d..88bef42 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.symlink_status/symlink_status.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.symlink_status/symlink_status.pass.cpp
@@ -13,11 +13,11 @@
 // file_status symlink_status(const path& p);
 // file_status symlink_status(const path& p, error_code& ec) noexcept;
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.temp_dir_path/temp_directory_path.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.temp_dir_path/temp_directory_path.pass.cpp
index fbce591..daa3c25 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.temp_dir_path/temp_directory_path.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.temp_dir_path/temp_directory_path.pass.cpp
@@ -13,15 +13,15 @@
 // path temp_directory_path();
 // path temp_directory_path(error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <memory>
 #include <cstdlib>
 #include <cstring>
 #include <cassert>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "filesystem_test_helper.hpp"
+#include "rapid-cxx-test.h"
+#include "filesystem_test_helper.h"
 
 using namespace fs;
 
diff --git a/test/std/input.output/filesystems/fs.op.funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp b/test/std/input.output/filesystems/fs.op.funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp
index 94a8e13..30e3a84 100644
--- a/test/std/input.output/filesystems/fs.op.funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp
+++ b/test/std/input.output/filesystems/fs.op.funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp
@@ -13,7 +13,7 @@
 // path weakly_canonical(const path& p);
 // path weakly_canonical(const path& p, error_code& ec);
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 #include <type_traits>
 #include <vector>
 #include <iostream>
@@ -21,8 +21,8 @@
 
 #include "test_macros.h"
 #include "test_iterators.h"
-#include "count_new.hpp"
-#include "filesystem_test_helper.hpp"
+#include "count_new.h"
+#include "filesystem_test_helper.h"
 
 
 int main(int, char**) {
diff --git a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.cons/container.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.cons/container.pass.cpp
index 8e1d7d1..0c43c15 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.cons/container.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.cons/container.pass.cpp
@@ -14,7 +14,7 @@
 
 #include <iterator>
 #include <vector>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/post.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/post.pass.cpp
index 34d72ed..c6f93d2 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/post.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/post.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/pre.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/pre.pass.cpp
index 551c7be..a104d46 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/pre.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op++/pre.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op_astrk/test.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op_astrk/test.pass.cpp
index 43b291a..22180f5 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op_astrk/test.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.insert.iter.op_astrk/test.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.inserter/test.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.inserter/test.pass.cpp
index eda9471..192d5a1 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.inserter/test.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/back.insert.iter.ops/back.inserter/test.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.cons/container.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.cons/container.pass.cpp
index 22c97bd..7fac5f3 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.cons/container.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.cons/container.pass.cpp
@@ -14,7 +14,7 @@
 
 #include <iterator>
 #include <list>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/post.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/post.pass.cpp
index 78bd85f..44a4271 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/post.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/post.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <list>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/pre.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/pre.pass.cpp
index 29c8f55..ac58374 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/pre.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op++/pre.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <list>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op=/lv_value.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op=/lv_value.pass.cpp
index 9cb8be5..ceeacb4 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op=/lv_value.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op=/lv_value.pass.cpp
@@ -16,7 +16,7 @@
 #include <iterator>
 #include <list>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op_astrk/test.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op_astrk/test.pass.cpp
index ac7a1fb..1c2e62e 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op_astrk/test.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.insert.iter.op_astrk/test.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <list>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.inserter/test.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.inserter/test.pass.cpp
index 2ce42da..e7e09c9 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.inserter/test.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/front.insert.iter.ops/front.inserter/test.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <list>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.cons/test.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.cons/test.pass.cpp
index f84df4d..c8650e4 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.cons/test.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.cons/test.pass.cpp
@@ -14,7 +14,7 @@
 
 #include <iterator>
 #include <vector>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/post.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/post.pass.cpp
index d2d7311..e8a1780 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/post.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/post.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/pre.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/pre.pass.cpp
index a4bd716..5f6a359 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/pre.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op++/pre.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op=/lv_value.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op=/lv_value.pass.cpp
index 783bf91..db7f123 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op=/lv_value.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op=/lv_value.pass.cpp
@@ -17,7 +17,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op_astrk/test.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op_astrk/test.pass.cpp
index c8e9240..57080a2 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op_astrk/test.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/insert.iter.op_astrk/test.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/inserter/test.pass.cpp b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/inserter/test.pass.cpp
index 7d499c0..77916a4 100644
--- a/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/inserter/test.pass.cpp
+++ b/test/std/iterators/predef.iterators/insert.iterators/insert.iter.ops/inserter/test.pass.cpp
@@ -15,7 +15,7 @@
 #include <iterator>
 #include <vector>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/language.support/support.dynamic/destroying_delete_t_declaration.pass.cpp b/test/std/language.support/support.dynamic/destroying_delete_t_declaration.pass.cpp
index b0e42ec..7eea424 100644
--- a/test/std/language.support/support.dynamic/destroying_delete_t_declaration.pass.cpp
+++ b/test/std/language.support/support.dynamic/destroying_delete_t_declaration.pass.cpp
@@ -24,7 +24,7 @@
 
 #include <cassert>
 #include "test_macros.h"
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 
 #ifdef __cpp_impl_destroying_delete
 # ifndef __cpp_lib_destroying_delete
diff --git a/test/std/localization/locale.categories/category.ctype/facet.ctype.special/facet.ctype.char.dtor/dtor.pass.cpp b/test/std/localization/locale.categories/category.ctype/facet.ctype.special/facet.ctype.char.dtor/dtor.pass.cpp
index 0f5f8d9..4296212 100644
--- a/test/std/localization/locale.categories/category.ctype/facet.ctype.special/facet.ctype.char.dtor/dtor.pass.cpp
+++ b/test/std/localization/locale.categories/category.ctype/facet.ctype.special/facet.ctype.char.dtor/dtor.pass.cpp
@@ -15,7 +15,7 @@
 #include <locale>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp b/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp
index 88892fb..bb69ef1 100644
--- a/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp
+++ b/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp
@@ -22,7 +22,7 @@
 #include <cstdlib>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp b/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp
index 30cb557..4fc4201 100644
--- a/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp
+++ b/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp
@@ -22,7 +22,7 @@
 #include <cstdlib>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/ctor.pass.cpp b/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/ctor.pass.cpp
index f28abb9..f879afb 100644
--- a/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/ctor.pass.cpp
+++ b/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/ctor.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 int main(int, char**)
 {
diff --git a/test/std/localization/locales/locale/locale.cons/assign.pass.cpp b/test/std/localization/locales/locale/locale.cons/assign.pass.cpp
index 969c945..049e014 100644
--- a/test/std/localization/locales/locale/locale.cons/assign.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/assign.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 #include <new>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
diff --git a/test/std/localization/locales/locale/locale.cons/char_pointer.pass.cpp b/test/std/localization/locales/locale/locale.cons/char_pointer.pass.cpp
index c324f39..76f8472 100644
--- a/test/std/localization/locales/locale/locale.cons/char_pointer.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/char_pointer.pass.cpp
@@ -20,7 +20,7 @@
 #include <new>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "platform_support.h" // locale name macros
 
 #include "test_macros.h"
diff --git a/test/std/localization/locales/locale/locale.cons/copy.pass.cpp b/test/std/localization/locales/locale/locale.cons/copy.pass.cpp
index 62aee24..a0e4762 100644
--- a/test/std/localization/locales/locale/locale.cons/copy.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/copy.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 #include <new>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
 
diff --git a/test/std/localization/locales/locale/locale.cons/default.pass.cpp b/test/std/localization/locales/locale/locale.cons/default.pass.cpp
index 614996b..b191aee 100644
--- a/test/std/localization/locales/locale/locale.cons/default.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/default.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
-#include "count_new.hpp"
+#include "count_new.h"
 
 void check(const std::locale& loc)
 {
diff --git a/test/std/localization/locales/locale/locale.cons/locale_char_pointer_cat.pass.cpp b/test/std/localization/locales/locale/locale.cons/locale_char_pointer_cat.pass.cpp
index 7064f6f..69324cb 100644
--- a/test/std/localization/locales/locale/locale.cons/locale_char_pointer_cat.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/locale_char_pointer_cat.pass.cpp
@@ -21,7 +21,7 @@
 #include <new>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
 
diff --git a/test/std/localization/locales/locale/locale.cons/locale_facetptr.pass.cpp b/test/std/localization/locales/locale/locale.cons/locale_facetptr.pass.cpp
index cac3fa9..0cc8af3 100644
--- a/test/std/localization/locales/locale/locale.cons/locale_facetptr.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/locale_facetptr.pass.cpp
@@ -16,7 +16,7 @@
 #include <new>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
 
diff --git a/test/std/localization/locales/locale/locale.cons/locale_locale_cat.pass.cpp b/test/std/localization/locales/locale/locale.cons/locale_locale_cat.pass.cpp
index fb7d595..e41d874 100644
--- a/test/std/localization/locales/locale/locale.cons/locale_locale_cat.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/locale_locale_cat.pass.cpp
@@ -21,7 +21,7 @@
 #include <new>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
 
diff --git a/test/std/localization/locales/locale/locale.cons/locale_string_cat.pass.cpp b/test/std/localization/locales/locale/locale.cons/locale_string_cat.pass.cpp
index d495036..219e934 100644
--- a/test/std/localization/locales/locale/locale.cons/locale_string_cat.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/locale_string_cat.pass.cpp
@@ -21,7 +21,7 @@
 #include <new>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
 
diff --git a/test/std/localization/locales/locale/locale.cons/string.pass.cpp b/test/std/localization/locales/locale/locale.cons/string.pass.cpp
index ee9ddbd..f6d621b 100644
--- a/test/std/localization/locales/locale/locale.cons/string.pass.cpp
+++ b/test/std/localization/locales/locale/locale.cons/string.pass.cpp
@@ -17,7 +17,7 @@
 #include <new>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 #include "platform_support.h" // locale name macros
 
diff --git a/test/std/localization/locales/locale/locale.members/combine.pass.cpp b/test/std/localization/locales/locale/locale.members/combine.pass.cpp
index fc1f3d3..68c0438 100644
--- a/test/std/localization/locales/locale/locale.members/combine.pass.cpp
+++ b/test/std/localization/locales/locale/locale.members/combine.pass.cpp
@@ -14,7 +14,7 @@
 #include <stdexcept>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp b/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
index eba6659..41a6f1e 100644
--- a/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
+++ b/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <string>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/strings/basic.string/string.cons/implicit_deduction_guides.pass.cpp b/test/std/strings/basic.string/string.cons/implicit_deduction_guides.pass.cpp
index 9e31d3e..82bd71b 100644
--- a/test/std/strings/basic.string/string.cons/implicit_deduction_guides.pass.cpp
+++ b/test/std/strings/basic.string/string.cons/implicit_deduction_guides.pass.cpp
@@ -21,7 +21,7 @@
 #include "test_macros.h"
 #include "test_allocator.h"
 #include "test_iterators.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class T, class Alloc = std::allocator<T>>
 using BStr = std::basic_string<T, std::char_traits<T>, Alloc>;
diff --git a/test/std/strings/string.view/string.view.comparison/opeq.string_view.pointer.pass.cpp b/test/std/strings/string.view/string.view.comparison/opeq.string_view.pointer.pass.cpp
index e771bd3..c13b47e 100644
--- a/test/std/strings/string.view/string.view.comparison/opeq.string_view.pointer.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opeq.string_view.pointer.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/opeq.string_view.string_view.pass.cpp b/test/std/strings/string.view/string.view.comparison/opeq.string_view.string_view.pass.cpp
index 259711e..3a5eeb7 100644
--- a/test/std/strings/string.view/string.view.comparison/opeq.string_view.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opeq.string_view.string_view.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/opge.string_view.pointer.pass.cpp b/test/std/strings/string.view/string.view.comparison/opge.string_view.pointer.pass.cpp
index 5fa57eb..e7db1e8 100644
--- a/test/std/strings/string.view/string.view.comparison/opge.string_view.pointer.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opge.string_view.pointer.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/opge.string_view.string_view.pass.cpp b/test/std/strings/string.view/string.view.comparison/opge.string_view.string_view.pass.cpp
index d35bea5..778157b 100644
--- a/test/std/strings/string.view/string.view.comparison/opge.string_view.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opge.string_view.string_view.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/opgt.string_view.pointer.pass.cpp b/test/std/strings/string.view/string.view.comparison/opgt.string_view.pointer.pass.cpp
index 80dcc7b..d39e902 100644
--- a/test/std/strings/string.view/string.view.comparison/opgt.string_view.pointer.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opgt.string_view.pointer.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/opgt.string_view.string_view.pass.cpp b/test/std/strings/string.view/string.view.comparison/opgt.string_view.string_view.pass.cpp
index ec31d5c..2f88ef2 100644
--- a/test/std/strings/string.view/string.view.comparison/opgt.string_view.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opgt.string_view.string_view.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/ople.string_view.pointer.pass.cpp b/test/std/strings/string.view/string.view.comparison/ople.string_view.pointer.pass.cpp
index 4f58223..3ad98b0 100644
--- a/test/std/strings/string.view/string.view.comparison/ople.string_view.pointer.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/ople.string_view.pointer.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/ople.string_view.string_view.pass.cpp b/test/std/strings/string.view/string.view.comparison/ople.string_view.string_view.pass.cpp
index b1c1861..267550a 100644
--- a/test/std/strings/string.view/string.view.comparison/ople.string_view.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/ople.string_view.string_view.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/oplt.string_view.pointer.pass.cpp b/test/std/strings/string.view/string.view.comparison/oplt.string_view.pointer.pass.cpp
index 14bba2a..2313c23 100644
--- a/test/std/strings/string.view/string.view.comparison/oplt.string_view.pointer.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/oplt.string_view.pointer.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/oplt.string_view.string_view.pass.cpp b/test/std/strings/string.view/string.view.comparison/oplt.string_view.string_view.pass.cpp
index f44e373..cefdab0 100644
--- a/test/std/strings/string.view/string.view.comparison/oplt.string_view.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/oplt.string_view.string_view.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/opne.string_view.pointer.pass.cpp b/test/std/strings/string.view/string.view.comparison/opne.string_view.pointer.pass.cpp
index 6b8add8..6bed63f 100644
--- a/test/std/strings/string.view/string.view.comparison/opne.string_view.pointer.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opne.string_view.pointer.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.comparison/opne.string_view.string_view.pass.cpp b/test/std/strings/string.view/string.view.comparison/opne.string_view.string_view.pass.cpp
index 90d1533..fac4c0d 100644
--- a/test/std/strings/string.view/string.view.comparison/opne.string_view.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.comparison/opne.string_view.string_view.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.cons/from_literal.pass.cpp b/test/std/strings/string.view/string.view.cons/from_literal.pass.cpp
index bcd83da..600ce72 100644
--- a/test/std/strings/string.view/string.view.cons/from_literal.pass.cpp
+++ b/test/std/strings/string.view/string.view.cons/from_literal.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template<typename CharT>
 size_t StrLen ( const CharT *s ) {
diff --git a/test/std/strings/string.view/string.view.cons/implicit_deduction_guides.pass.cpp b/test/std/strings/string.view/string.view.cons/implicit_deduction_guides.pass.cpp
index b95dca6..9cea8c6 100644
--- a/test/std/strings/string.view/string.view.cons/implicit_deduction_guides.pass.cpp
+++ b/test/std/strings/string.view/string.view.cons/implicit_deduction_guides.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 // Overloads
 // ---------------
diff --git a/test/std/strings/string.view/string.view.find/find_char_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_char_size.pass.cpp
index 82173a9..15dff2e 100644
--- a/test/std/strings/string.view/string.view.find/find_char_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_char_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_first_not_of_char_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_first_not_of_char_size.pass.cpp
index 4566ada..1b050dd 100644
--- a/test/std/strings/string.view/string.view.find/find_first_not_of_char_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_first_not_of_char_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size.pass.cpp
index 17c3c52..535860e 100644
--- a/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size_size.pass.cpp
index 707a7a9..18fdda9 100644
--- a/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_first_not_of_pointer_size_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_first_of_char_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_first_of_char_size.pass.cpp
index d4916be..b1bda4e 100644
--- a/test/std/strings/string.view/string.view.find/find_first_of_char_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_first_of_char_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_first_of_pointer_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_first_of_pointer_size.pass.cpp
index 7e43109..ee50e0c 100644
--- a/test/std/strings/string.view/string.view.find/find_first_of_pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_first_of_pointer_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_first_of_pointer_size_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_first_of_pointer_size_size.pass.cpp
index 165fb23..5e35f4c 100644
--- a/test/std/strings/string.view/string.view.find/find_first_of_pointer_size_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_first_of_pointer_size_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_last_not_of_char_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_last_not_of_char_size.pass.cpp
index 0b6e6cf..c4c7fa4 100644
--- a/test/std/strings/string.view/string.view.find/find_last_not_of_char_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_last_not_of_char_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size.pass.cpp
index fe17b77..48574cd 100644
--- a/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size_size.pass.cpp
index 11a5c27..3e46ed8 100644
--- a/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_last_not_of_pointer_size_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_last_of_char_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_last_of_char_size.pass.cpp
index fdcf317..0f8c6b0 100644
--- a/test/std/strings/string.view/string.view.find/find_last_of_char_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_last_of_char_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_last_of_pointer_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_last_of_pointer_size.pass.cpp
index 640f483..4b2e8c8 100644
--- a/test/std/strings/string.view/string.view.find/find_last_of_pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_last_of_pointer_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_last_of_pointer_size_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_last_of_pointer_size_size.pass.cpp
index e82c935..318b211 100644
--- a/test/std/strings/string.view/string.view.find/find_last_of_pointer_size_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_last_of_pointer_size_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_pointer_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_pointer_size.pass.cpp
index 3f4fee5..67c01ec 100644
--- a/test/std/strings/string.view/string.view.find/find_pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_pointer_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_pointer_size_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_pointer_size_size.pass.cpp
index 74caa6f..dd5536b 100644
--- a/test/std/strings/string.view/string.view.find/find_pointer_size_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_pointer_size_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/find_string_view_size.pass.cpp b/test/std/strings/string.view/string.view.find/find_string_view_size.pass.cpp
index ed3b7c1..6f4aa90 100644
--- a/test/std/strings/string.view/string.view.find/find_string_view_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/find_string_view_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/rfind_char_size.pass.cpp b/test/std/strings/string.view/string.view.find/rfind_char_size.pass.cpp
index 959bb05..e8229e1 100644
--- a/test/std/strings/string.view/string.view.find/rfind_char_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/rfind_char_size.pass.cpp
@@ -13,7 +13,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/rfind_pointer_size.pass.cpp b/test/std/strings/string.view/string.view.find/rfind_pointer_size.pass.cpp
index 6010083..691fab4 100644
--- a/test/std/strings/string.view/string.view.find/rfind_pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/rfind_pointer_size.pass.cpp
@@ -13,7 +13,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/rfind_pointer_size_size.pass.cpp b/test/std/strings/string.view/string.view.find/rfind_pointer_size_size.pass.cpp
index c3ca97e..39a295d 100644
--- a/test/std/strings/string.view/string.view.find/rfind_pointer_size_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/rfind_pointer_size_size.pass.cpp
@@ -13,7 +13,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.find/rfind_string_view_size.pass.cpp b/test/std/strings/string.view/string.view.find/rfind_string_view_size.pass.cpp
index c4ceef3..7607bcf 100644
--- a/test/std/strings/string.view/string.view.find/rfind_string_view_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.find/rfind_string_view_size.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 template <class S>
 void
diff --git a/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp b/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp
index 8363b00..64fa807 100644
--- a/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp
+++ b/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <string_view>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/strings/string.view/string.view.ops/compare.pointer.pass.cpp b/test/std/strings/string.view/string.view.ops/compare.pointer.pass.cpp
index cdddea1..a48186b 100644
--- a/test/std/strings/string.view/string.view.ops/compare.pointer.pass.cpp
+++ b/test/std/strings/string.view/string.view.ops/compare.pointer.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
 
diff --git a/test/std/strings/string.view/string.view.ops/compare.pointer_size.pass.cpp b/test/std/strings/string.view/string.view.ops/compare.pointer_size.pass.cpp
index 3d40148..a3b7b6c 100644
--- a/test/std/strings/string.view/string.view.ops/compare.pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.ops/compare.pointer_size.pass.cpp
@@ -15,7 +15,7 @@
 #include <stdexcept>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
 
diff --git a/test/std/strings/string.view/string.view.ops/compare.size_size_sv.pass.cpp b/test/std/strings/string.view/string.view.ops/compare.size_size_sv.pass.cpp
index 1bd26b3..4088e2f 100644
--- a/test/std/strings/string.view/string.view.ops/compare.size_size_sv.pass.cpp
+++ b/test/std/strings/string.view/string.view.ops/compare.size_size_sv.pass.cpp
@@ -15,7 +15,7 @@
 #include <stdexcept>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
 
diff --git a/test/std/strings/string.view/string.view.ops/compare.size_size_sv_pointer_size.pass.cpp b/test/std/strings/string.view/string.view.ops/compare.size_size_sv_pointer_size.pass.cpp
index 73ef1ea..1409f08 100644
--- a/test/std/strings/string.view/string.view.ops/compare.size_size_sv_pointer_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.ops/compare.size_size_sv_pointer_size.pass.cpp
@@ -16,7 +16,7 @@
 #include <stdexcept>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
 
diff --git a/test/std/strings/string.view/string.view.ops/compare.size_size_sv_size_size.pass.cpp b/test/std/strings/string.view/string.view.ops/compare.size_size_sv_size_size.pass.cpp
index f6a21d0..ef81db6 100644
--- a/test/std/strings/string.view/string.view.ops/compare.size_size_sv_size_size.pass.cpp
+++ b/test/std/strings/string.view/string.view.ops/compare.size_size_sv_size_size.pass.cpp
@@ -16,7 +16,7 @@
 #include <stdexcept>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
 
diff --git a/test/std/strings/string.view/string.view.ops/compare.sv.pass.cpp b/test/std/strings/string.view/string.view.ops/compare.sv.pass.cpp
index 9c27f26..72e8dee 100644
--- a/test/std/strings/string.view/string.view.ops/compare.sv.pass.cpp
+++ b/test/std/strings/string.view/string.view.ops/compare.sv.pass.cpp
@@ -14,7 +14,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
 
diff --git a/test/std/strings/string.view/string.view.template/ends_with.char.pass.cpp b/test/std/strings/string.view/string.view.template/ends_with.char.pass.cpp
index c037330..6f23127 100644
--- a/test/std/strings/string.view/string.view.template/ends_with.char.pass.cpp
+++ b/test/std/strings/string.view/string.view.template/ends_with.char.pass.cpp
@@ -15,7 +15,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int main(int, char**)
 {
diff --git a/test/std/strings/string.view/string.view.template/ends_with.ptr.pass.cpp b/test/std/strings/string.view/string.view.template/ends_with.ptr.pass.cpp
index 64caf5c..511fad2 100644
--- a/test/std/strings/string.view/string.view.template/ends_with.ptr.pass.cpp
+++ b/test/std/strings/string.view/string.view.template/ends_with.ptr.pass.cpp
@@ -15,7 +15,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int main(int, char**)
 {
diff --git a/test/std/strings/string.view/string.view.template/ends_with.string_view.pass.cpp b/test/std/strings/string.view/string.view.template/ends_with.string_view.pass.cpp
index b5f67f8..405214f 100644
--- a/test/std/strings/string.view/string.view.template/ends_with.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.template/ends_with.string_view.pass.cpp
@@ -15,7 +15,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int main(int, char**)
 {
diff --git a/test/std/strings/string.view/string.view.template/starts_with.char.pass.cpp b/test/std/strings/string.view/string.view.template/starts_with.char.pass.cpp
index d43944f..0cf0663 100644
--- a/test/std/strings/string.view/string.view.template/starts_with.char.pass.cpp
+++ b/test/std/strings/string.view/string.view.template/starts_with.char.pass.cpp
@@ -15,7 +15,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int main(int, char**)
 {
diff --git a/test/std/strings/string.view/string.view.template/starts_with.ptr.pass.cpp b/test/std/strings/string.view/string.view.template/starts_with.ptr.pass.cpp
index ce651ec..3ec9746 100644
--- a/test/std/strings/string.view/string.view.template/starts_with.ptr.pass.cpp
+++ b/test/std/strings/string.view/string.view.template/starts_with.ptr.pass.cpp
@@ -15,7 +15,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int main(int, char**)
 {
diff --git a/test/std/strings/string.view/string.view.template/starts_with.string_view.pass.cpp b/test/std/strings/string.view/string.view.template/starts_with.string_view.pass.cpp
index 3d184ba..8262427 100644
--- a/test/std/strings/string.view/string.view.template/starts_with.string_view.pass.cpp
+++ b/test/std/strings/string.view/string.view.template/starts_with.string_view.pass.cpp
@@ -15,7 +15,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "constexpr_char_traits.hpp"
+#include "constexpr_char_traits.h"
 
 int main(int, char**)
 {
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_assign.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_assign.pass.cpp
index 8145a40..354f17d 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_assign.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_assign.pass.cpp
@@ -18,7 +18,7 @@
 
 #include <shared_mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_ctor.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_ctor.pass.cpp
index ee5b55d..e413f62 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_ctor.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_ctor.pass.cpp
@@ -18,7 +18,7 @@
 
 #include <shared_mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_adopt_lock.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_adopt_lock.pass.cpp
index 573fbfd..6d95185 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_adopt_lock.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_adopt_lock.pass.cpp
@@ -18,7 +18,7 @@
 
 #include <shared_mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_defer_lock.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_defer_lock.pass.cpp
index 053b4dd..f6bb847 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_defer_lock.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_defer_lock.pass.cpp
@@ -18,7 +18,7 @@
 
 #include <shared_mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_assign.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_assign.pass.cpp
index 3fc00b5..529baae 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_assign.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_assign.pass.cpp
@@ -16,7 +16,7 @@
 
 #include <mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_ctor.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_ctor.pass.cpp
index f3440a9..6f033db 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_ctor.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/move_ctor.pass.cpp
@@ -16,7 +16,7 @@
 
 #include <mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_adopt_lock.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_adopt_lock.pass.cpp
index e599ca5..9d723aa 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_adopt_lock.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_adopt_lock.pass.cpp
@@ -16,7 +16,7 @@
 
 #include <mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_defer_lock.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_defer_lock.pass.cpp
index 1224a8c..a16dcbe 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_defer_lock.pass.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_defer_lock.pass.cpp
@@ -16,7 +16,7 @@
 
 #include <mutex>
 #include <cassert>
-#include "nasty_containers.hpp"
+#include "nasty_containers.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/thread/thread.threads/thread.thread.class/thread.thread.id/enabled_hashes.pass.cpp b/test/std/thread/thread.threads/thread.thread.class/thread.thread.id/enabled_hashes.pass.cpp
index 48cb83b..624d05c 100644
--- a/test/std/thread/thread.threads/thread.thread.class/thread.thread.id/enabled_hashes.pass.cpp
+++ b/test/std/thread/thread.threads/thread.thread.class/thread.thread.id/enabled_hashes.pass.cpp
@@ -16,7 +16,7 @@
 
 #include <thread>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair.pass.cpp b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair.pass.cpp
index 9748d66..ae2ed0d 100644
--- a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair.pass.cpp
+++ b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair.pass.cpp
@@ -22,8 +22,8 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_const_lvalue_pair.pass.cpp b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_const_lvalue_pair.pass.cpp
index 103f8f4..4fc4794 100644
--- a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_const_lvalue_pair.pass.cpp
+++ b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_const_lvalue_pair.pass.cpp
@@ -22,8 +22,8 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_piecewise.pass.cpp b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_piecewise.pass.cpp
index d8f5e7c..2ada281 100644
--- a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_piecewise.pass.cpp
+++ b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_piecewise.pass.cpp
@@ -23,8 +23,8 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_rvalue.pass.cpp b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_rvalue.pass.cpp
index 5632e21..ed8785b 100644
--- a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_rvalue.pass.cpp
+++ b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_rvalue.pass.cpp
@@ -22,8 +22,8 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_values.pass.cpp b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_values.pass.cpp
index 9ba2d15..3a4c236 100644
--- a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_values.pass.cpp
+++ b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_pair_values.pass.cpp
@@ -22,8 +22,8 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_type.pass.cpp b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_type.pass.cpp
index 2dee95d..5a919d3 100644
--- a/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_type.pass.cpp
+++ b/test/std/utilities/allocator.adaptor/allocator.adaptor.members/construct_type.pass.cpp
@@ -22,8 +22,8 @@
 #include <tuple>
 #include <cassert>
 #include <cstdlib>
-#include "uses_alloc_types.hpp"
-#include "controlled_allocators.hpp"
+#include "uses_alloc_types.h"
+#include "controlled_allocators.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/any/any.class/any.assign/copy.pass.cpp b/test/std/utilities/any/any.class/any.assign/copy.pass.cpp
index d818400..7f44afe 100644
--- a/test/std/utilities/any/any.class/any.assign/copy.pass.cpp
+++ b/test/std/utilities/any/any.class/any.assign/copy.pass.cpp
@@ -20,7 +20,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/any/any.class/any.assign/value.pass.cpp b/test/std/utilities/any/any.class/any.assign/value.pass.cpp
index 8ca93df..5ac9b79 100644
--- a/test/std/utilities/any/any.class/any.assign/value.pass.cpp
+++ b/test/std/utilities/any/any.class/any.assign/value.pass.cpp
@@ -21,7 +21,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/any/any.class/any.cons/copy.pass.cpp b/test/std/utilities/any/any.class/any.cons/copy.pass.cpp
index fbb5f18..de29901 100644
--- a/test/std/utilities/any/any.class/any.cons/copy.pass.cpp
+++ b/test/std/utilities/any/any.class/any.cons/copy.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/any/any.class/any.cons/default.pass.cpp b/test/std/utilities/any/any.class/any.cons/default.pass.cpp
index 6cd7b89..159bf75 100644
--- a/test/std/utilities/any/any.class/any.cons/default.pass.cpp
+++ b/test/std/utilities/any/any.class/any.cons/default.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/any/any.class/any.cons/in_place_type.pass.cpp b/test/std/utilities/any/any.class/any.cons/in_place_type.pass.cpp
index bfe86e8..329322d 100644
--- a/test/std/utilities/any/any.class/any.cons/in_place_type.pass.cpp
+++ b/test/std/utilities/any/any.class/any.cons/in_place_type.pass.cpp
@@ -27,9 +27,9 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 
 using std::any;
 using std::any_cast;
diff --git a/test/std/utilities/any/any.class/any.cons/move.pass.cpp b/test/std/utilities/any/any.class/any.cons/move.pass.cpp
index 3c0780c..ac88e0f 100644
--- a/test/std/utilities/any/any.class/any.cons/move.pass.cpp
+++ b/test/std/utilities/any/any.class/any.cons/move.pass.cpp
@@ -20,7 +20,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/any/any.class/any.cons/value.pass.cpp b/test/std/utilities/any/any.class/any.cons/value.pass.cpp
index e39c730..ecd3bd7 100644
--- a/test/std/utilities/any/any.class/any.cons/value.pass.cpp
+++ b/test/std/utilities/any/any.class/any.cons/value.pass.cpp
@@ -25,7 +25,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/any/any.class/any.modifiers/emplace.pass.cpp b/test/std/utilities/any/any.class/any.modifiers/emplace.pass.cpp
index 8a5e433..e2b232b 100644
--- a/test/std/utilities/any/any.class/any.modifiers/emplace.pass.cpp
+++ b/test/std/utilities/any/any.class/any.modifiers/emplace.pass.cpp
@@ -20,7 +20,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/any/any.nonmembers/any.cast/any_cast_reference.pass.cpp b/test/std/utilities/any/any.nonmembers/any.cast/any_cast_reference.pass.cpp
index 1216444..faaca94 100644
--- a/test/std/utilities/any/any.nonmembers/any.cast/any_cast_reference.pass.cpp
+++ b/test/std/utilities/any/any.nonmembers/any.cast/any_cast_reference.pass.cpp
@@ -26,7 +26,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/any/any.nonmembers/make_any.pass.cpp b/test/std/utilities/any/any.nonmembers/make_any.pass.cpp
index 9c5dda2..5e319ef 100644
--- a/test/std/utilities/any/any.nonmembers/make_any.pass.cpp
+++ b/test/std/utilities/any/any.nonmembers/make_any.pass.cpp
@@ -20,7 +20,7 @@
 #include <cassert>
 
 #include "any_helpers.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 
 using std::any;
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.alg/swap.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.alg/swap.pass.cpp
index ec25bdf..cf3477f 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.alg/swap.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.alg/swap.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 class A
 {
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F.pass.cpp
index fe5d248..5944f59 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 class A
 {
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F_assign.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F_assign.pass.cpp
index f70a208..2617855 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F_assign.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/F_assign.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 class A
 {
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_F.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_F.pass.cpp
index bcc93ad..f21f8d4 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_F.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_F.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 #include "test_allocator.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "../function_types.h"
 
 
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_function.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_function.pass.cpp
index 3f3b5c6..138f3d9 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_function.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_function.pass.cpp
@@ -20,7 +20,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 #include "test_allocator.h"
-#include "count_new.hpp"
+#include "count_new.h"
 #include "../function_types.h"
 
 class DummyClass {};
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_rfunction.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_rfunction.pass.cpp
index 064046d..46f33be 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_rfunction.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/alloc_rfunction.pass.cpp
@@ -23,7 +23,7 @@
 
 #include "test_macros.h"
 #include "min_allocator.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 class A
 {
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_assign.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_assign.pass.cpp
index d7b11ae..d97b699 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_assign.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_assign.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 class A {
   int data_[10];
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_move.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_move.pass.cpp
index dbbde5c..b756e7e 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_move.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/copy_move.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 class A
 {
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign.pass.cpp
index 00ab664..16d9f05 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.con/nullptr_t_assign.pass.cpp
@@ -15,7 +15,7 @@
 #include <functional>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.mod/swap.pass.cpp b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.mod/swap.pass.cpp
index 8c8f3f5..f034eb7 100644
--- a/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.mod/swap.pass.cpp
+++ b/test/std/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.mod/swap.pass.cpp
@@ -15,7 +15,7 @@
 #include <functional>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_2.pass.cpp b/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_2.pass.cpp
index 8e5e7c3..8761357 100644
--- a/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_2.pass.cpp
+++ b/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_2.pass.cpp
@@ -15,7 +15,7 @@
 #include <functional>
 #include <cassert>
 
-#include "counting_predicates.hpp"
+#include "counting_predicates.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/function.objects/unord.hash/enabled_hashes.pass.cpp b/test/std/utilities/function.objects/unord.hash/enabled_hashes.pass.cpp
index c871154..8f29b2a 100644
--- a/test/std/utilities/function.objects/unord.hash/enabled_hashes.pass.cpp
+++ b/test/std/utilities/function.objects/unord.hash/enabled_hashes.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <functional>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp b/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp
index fac99d1..cdf491b 100644
--- a/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp
+++ b/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp
@@ -16,7 +16,7 @@
 #include <cstddef>       // for std::max_align_t
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 
 #ifdef TEST_HAS_NO_ALIGNED_ALLOCATION
diff --git a/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp b/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp
index 96954e0..328603b 100644
--- a/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp
+++ b/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp
@@ -15,7 +15,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 int A_constructed = 0;
 
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
index fe7567e..8dd984d 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
@@ -25,7 +25,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 struct T
     : public std::enable_shared_from_this<T>
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp
index 677354e..a5a1a21 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <memory>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp
index 0fcf27f..9b695cf 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp
@@ -20,7 +20,7 @@
 #include <cassert>
 
 #if TEST_STD_VER >= 11
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp
index 5cae6ca..5d25bd7 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp
@@ -22,7 +22,7 @@
 #include "test_macros.h"
 
 #if TEST_STD_VER >= 11
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 #include "deleter_types.h"
 #include "min_allocator.h"
 
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp
index 6b12d75..5e9e06f 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 struct B
 {
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp
index 7d2628d..795717f 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp
@@ -21,7 +21,7 @@
 #include <cstdlib>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "deleter_types.h"
 
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp
index 9fa3271..4a5ae75 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp
@@ -20,7 +20,7 @@
 #include <new>
 #include <cstdlib>
 
-#include "count_new.hpp"
+#include "count_new.h"
 #include "test_macros.h"
 #include "deleter_types.h"
 
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp
index b7b5d14..fd33ce9 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp
@@ -19,7 +19,7 @@
 #include <cstdlib>
 #include <cassert>
 
-#include "count_new.hpp"
+#include "count_new.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp
index 6fd812f..41e64c6 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 struct B
 {
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp
index aed060e..ebb1cdc 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "count_new.hpp"
+#include "count_new.h"
 
 #if TEST_STD_VER >= 11
 #define DELETE_FUNCTION = delete
diff --git a/test/std/utilities/optional/optional.hash/enabled_hash.pass.cpp b/test/std/utilities/optional/optional.hash/enabled_hash.pass.cpp
index fc84e6d..212ffec 100644
--- a/test/std/utilities/optional/optional.hash/enabled_hash.pass.cpp
+++ b/test/std/utilities/optional/optional.hash/enabled_hash.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <optional>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/optional/optional.hash/hash.pass.cpp b/test/std/utilities/optional/optional.hash/hash.pass.cpp
index d4f0416..9645e31 100644
--- a/test/std/utilities/optional/optional.hash/hash.pass.cpp
+++ b/test/std/utilities/optional/optional.hash/hash.pass.cpp
@@ -16,7 +16,7 @@
 #include <memory>
 #include <cassert>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
index 3dd28ac..d3953af 100644
--- a/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
@@ -17,7 +17,7 @@
 #include <memory>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
index 6ccaafa..cf44921 100644
--- a/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
index 5900e60..a5ff102 100644
--- a/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
index c5cebc5..d05f40d 100644
--- a/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
@@ -17,7 +17,7 @@
 #include <memory>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
index c862c5f..bdaf6ff 100644
--- a/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
@@ -19,7 +19,7 @@
 #include <utility>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
index af582d7..c0beecc 100644
--- a/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 using std::nullopt_t;
diff --git a/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
index cabaa07..2239aca 100644
--- a/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
index b5966df..ce0b6e5 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
@@ -20,8 +20,8 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 
 
 using std::optional;
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/const_T.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/const_T.pass.cpp
index f20a840..018abd9 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/const_T.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/const_T.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
index e6793cd..db38cbf 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/default.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/default.pass.cpp
index 3dd38da..4b4d64e 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/default.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/default.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/empty_in_place_t_does_not_clobber.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/empty_in_place_t_does_not_clobber.pass.cpp
index 84db7ea..7936390 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/empty_in_place_t_does_not_clobber.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/empty_in_place_t_does_not_clobber.pass.cpp
@@ -20,7 +20,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
index 4c58d45..fc2c461 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp
index 12b19a7..30214fb 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp
@@ -15,7 +15,7 @@
 #include <type_traits>
 #include <cassert>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp
index f2e7882..3d9e942 100644
--- a/test/std/utilities/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp
@@ -19,7 +19,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 
 using std::optional;
diff --git a/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
index e881a0c..15fb2b0 100644
--- a/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
+++ b/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/optional/optional.object/special_members.pass.cpp b/test/std/utilities/optional/optional.object/special_members.pass.cpp
index 2449801..6a5fb92 100644
--- a/test/std/utilities/optional/optional.object/special_members.pass.cpp
+++ b/test/std/utilities/optional/optional.object/special_members.pass.cpp
@@ -16,7 +16,7 @@
 #include <optional>
 #include <type_traits>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/optional/optional.object/triviality.pass.cpp b/test/std/utilities/optional/optional.object/triviality.pass.cpp
index 3af60a6..1aff9df 100644
--- a/test/std/utilities/optional/optional.object/triviality.pass.cpp
+++ b/test/std/utilities/optional/optional.object/triviality.pass.cpp
@@ -22,7 +22,7 @@
 #include <optional>
 #include <type_traits>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/optional/optional.specalg/swap.pass.cpp b/test/std/utilities/optional/optional.specalg/swap.pass.cpp
index 1a548e8..4fca6e0 100644
--- a/test/std/utilities/optional/optional.specalg/swap.pass.cpp
+++ b/test/std/utilities/optional/optional.specalg/swap.pass.cpp
@@ -17,7 +17,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 using std::optional;
 
diff --git a/test/std/utilities/template.bitset/bitset.hash/enabled_hash.pass.cpp b/test/std/utilities/template.bitset/bitset.hash/enabled_hash.pass.cpp
index 5adc060..621caa4 100644
--- a/test/std/utilities/template.bitset/bitset.hash/enabled_hash.pass.cpp
+++ b/test/std/utilities/template.bitset/bitset.hash/enabled_hash.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <bitset>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.pass.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.pass.cpp
index 916255c..6a06afa 100644
--- a/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.pass.cpp
+++ b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.pass.cpp
@@ -20,7 +20,7 @@
 #include <type_traits>
 
 #include "test_macros.h"
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "MoveOnly.h"
 
 #if TEST_STD_VER > 11
diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/deduct.pass.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/deduct.pass.cpp
index ddb61a0..4944f64 100644
--- a/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/deduct.pass.cpp
+++ b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/deduct.pass.cpp
@@ -26,7 +26,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 
 // Overloads
diff --git a/test/std/utilities/type.index/type.index.hash/enabled_hash.pass.cpp b/test/std/utilities/type.index/type.index.hash/enabled_hash.pass.cpp
index e663071..d8c9ce0 100644
--- a/test/std/utilities/type.index/type.index.hash/enabled_hash.pass.cpp
+++ b/test/std/utilities/type.index/type.index.hash/enabled_hash.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <typeindex>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/type.index/type.index.synopsis/hash_type_index.pass.cpp b/test/std/utilities/type.index/type.index.synopsis/hash_type_index.pass.cpp
index e8ce292..605aa99 100644
--- a/test/std/utilities/type.index/type.index.synopsis/hash_type_index.pass.cpp
+++ b/test/std/utilities/type.index/type.index.synopsis/hash_type_index.pass.cpp
@@ -19,7 +19,7 @@
 
 #include "test_macros.h"
 #if TEST_STD_VER >= 11
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 #endif
 
 int main(int, char**)
diff --git a/test/std/utilities/utility/pairs/pairs.pair/U_V.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/U_V.pass.cpp
index dc4cd31..062ef62 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/U_V.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/U_V.pass.cpp
@@ -19,8 +19,8 @@
 #include <memory>
 #include <cassert>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 
 #include "test_macros.h"
 using namespace ImplicitTypes; // Get implicitly archetypes
diff --git a/test/std/utilities/utility/pairs/pairs.pair/assign_const_pair_U_V.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/assign_const_pair_U_V.pass.cpp
index 834d73d..078d424 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/assign_const_pair_U_V.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/assign_const_pair_U_V.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 #if TEST_STD_VER >= 11
-#include "archetypes.hpp"
+#include "archetypes.h"
 #endif
 
 int main(int, char**)
diff --git a/test/std/utilities/utility/pairs/pairs.pair/assign_rv_pair_U_V.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/assign_rv_pair_U_V.pass.cpp
index 64e3adb..17d6020 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/assign_rv_pair_U_V.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/assign_rv_pair_U_V.pass.cpp
@@ -17,7 +17,7 @@
 #include <utility>
 #include <memory>
 #include <cassert>
-#include <archetypes.hpp>
+#include <archetypes.h>
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/utility/pairs/pairs.pair/const_first_const_second.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/const_first_const_second.pass.cpp
index 53c6cc8..621ab55 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/const_first_const_second.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/const_first_const_second.pass.cpp
@@ -17,8 +17,8 @@
 #include <utility>
 #include <cassert>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 
 #include "test_macros.h"
 using namespace ImplicitTypes; // Get implicitly archetypes
diff --git a/test/std/utilities/utility/pairs/pairs.pair/const_pair_U_V.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/const_pair_U_V.pass.cpp
index 5a592c3..6d9e81c 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/const_pair_U_V.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/const_pair_U_V.pass.cpp
@@ -17,8 +17,8 @@
 #include <utility>
 #include <cassert>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 
 #include "test_macros.h"
 using namespace ImplicitTypes; // Get implicitly archetypes
diff --git a/test/std/utilities/utility/pairs/pairs.pair/default.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/default.pass.cpp
index dc1f37b..de3730e 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/default.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/default.pass.cpp
@@ -26,7 +26,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/utility/pairs/pairs.pair/implicit_deduction_guides.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/implicit_deduction_guides.pass.cpp
index ca5a728..4e3559f 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/implicit_deduction_guides.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/implicit_deduction_guides.pass.cpp
@@ -26,7 +26,7 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 
 // Overloads
diff --git a/test/std/utilities/utility/pairs/pairs.pair/rv_pair_U_V.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/rv_pair_U_V.pass.cpp
index 3d12398..a3f2464 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/rv_pair_U_V.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/rv_pair_U_V.pass.cpp
@@ -18,8 +18,8 @@
 #include <memory>
 #include <cassert>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 
 #include "test_macros.h"
 using namespace ImplicitTypes; // Get implicitly archetypes
diff --git a/test/std/utilities/utility/pairs/pairs.pair/special_member_generation_test.pass.cpp b/test/std/utilities/utility/pairs/pairs.pair/special_member_generation_test.pass.cpp
index b1082cc..449a27c 100644
--- a/test/std/utilities/utility/pairs/pairs.pair/special_member_generation_test.pass.cpp
+++ b/test/std/utilities/utility/pairs/pairs.pair/special_member_generation_test.pass.cpp
@@ -24,7 +24,7 @@
 #include <string>
 #include <tuple>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 
 #include "test_macros.h"
 using namespace ImplicitTypes; // Get implicitly archetypes
diff --git a/test/std/utilities/variant/variant.get/get_if_index.pass.cpp b/test/std/utilities/variant/variant.get/get_if_index.pass.cpp
index 5210c5f..827f7a2 100644
--- a/test/std/utilities/variant/variant.get/get_if_index.pass.cpp
+++ b/test/std/utilities/variant/variant.get/get_if_index.pass.cpp
@@ -19,7 +19,7 @@
 //   get_if(const variant<Types...>* v) noexcept;
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 #include <cassert>
 #include <memory>
 #include <variant>
diff --git a/test/std/utilities/variant/variant.get/get_if_type.pass.cpp b/test/std/utilities/variant/variant.get/get_if_type.pass.cpp
index e7c9671..341d539 100644
--- a/test/std/utilities/variant/variant.get/get_if_type.pass.cpp
+++ b/test/std/utilities/variant/variant.get/get_if_type.pass.cpp
@@ -18,7 +18,7 @@
 //  noexcept;
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 #include <cassert>
 #include <variant>
 
diff --git a/test/std/utilities/variant/variant.get/get_index.pass.cpp b/test/std/utilities/variant/variant.get/get_index.pass.cpp
index d8711c7..16e2f20 100644
--- a/test/std/utilities/variant/variant.get/get_index.pass.cpp
+++ b/test/std/utilities/variant/variant.get/get_index.pass.cpp
@@ -28,7 +28,7 @@
 
 #include "test_macros.h"
 #include "test_workarounds.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 #include <cassert>
 #include <type_traits>
 #include <utility>
diff --git a/test/std/utilities/variant/variant.get/get_type.pass.cpp b/test/std/utilities/variant/variant.get/get_type.pass.cpp
index 5272c09..333f3d9 100644
--- a/test/std/utilities/variant/variant.get/get_type.pass.cpp
+++ b/test/std/utilities/variant/variant.get/get_type.pass.cpp
@@ -22,7 +22,7 @@
 
 #include "test_macros.h"
 #include "test_workarounds.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 #include <cassert>
 #include <type_traits>
 #include <utility>
diff --git a/test/std/utilities/variant/variant.hash/enabled_hash.pass.cpp b/test/std/utilities/variant/variant.hash/enabled_hash.pass.cpp
index 2649dd6..f5e0fbe 100644
--- a/test/std/utilities/variant/variant.hash/enabled_hash.pass.cpp
+++ b/test/std/utilities/variant/variant.hash/enabled_hash.pass.cpp
@@ -15,7 +15,7 @@
 
 #include <variant>
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/std/utilities/variant/variant.hash/hash.pass.cpp b/test/std/utilities/variant/variant.hash/hash.pass.cpp
index edda8d2..a425518 100644
--- a/test/std/utilities/variant/variant.hash/hash.pass.cpp
+++ b/test/std/utilities/variant/variant.hash/hash.pass.cpp
@@ -19,8 +19,8 @@
 #include <variant>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
-#include "poisoned_hash_helper.hpp"
+#include "variant_test_helpers.h"
+#include "poisoned_hash_helper.h"
 
 #ifndef TEST_HAS_NO_EXCEPTIONS
 namespace std {
diff --git a/test/std/utilities/variant/variant.helpers/variant_alternative.pass.cpp b/test/std/utilities/variant/variant.helpers/variant_alternative.pass.cpp
index 7db07b6..e8b6302 100644
--- a/test/std/utilities/variant/variant.helpers/variant_alternative.pass.cpp
+++ b/test/std/utilities/variant/variant.helpers/variant_alternative.pass.cpp
@@ -26,7 +26,7 @@
 #include <variant>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 template <class V, size_t I, class E> void test() {
   static_assert(
diff --git a/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp b/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
index ab4ea7e..3483298 100644
--- a/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
@@ -25,7 +25,7 @@
 #include <memory>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 namespace MetaHelpers {
 
diff --git a/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp b/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp
index b16cf2c..a1d9122 100644
--- a/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp
@@ -20,7 +20,7 @@
 #include <string>
 #include <memory>
 
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/variant/variant.variant/variant.assign/move.pass.cpp b/test/std/utilities/variant/variant.variant/variant.assign/move.pass.cpp
index 990e10c..7ec76ab 100644
--- a/test/std/utilities/variant/variant.variant/variant.assign/move.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.assign/move.pass.cpp
@@ -29,7 +29,7 @@
 #include <variant>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 struct NoCopy {
   NoCopy(const NoCopy &) = delete;
diff --git a/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp b/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp
index 42a31f3..0824761 100644
--- a/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp
@@ -23,7 +23,7 @@
 #include <memory>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 struct Dummy {
   Dummy() = default;
diff --git a/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp b/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp
index 4799123..c0b1560 100644
--- a/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp
@@ -19,7 +19,7 @@
 #include <string>
 #include <memory>
 
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/variant/variant.variant/variant.ctor/default.pass.cpp b/test/std/utilities/variant/variant.variant/variant.ctor/default.pass.cpp
index 579ae4d..a26abf5 100644
--- a/test/std/utilities/variant/variant.variant/variant.ctor/default.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.ctor/default.pass.cpp
@@ -22,7 +22,7 @@
 #include <variant>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 struct NonDefaultConstructible {
   constexpr NonDefaultConstructible(int) {}
diff --git a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_args.pass.cpp
index ac736fb..f404c0b 100644
--- a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_args.pass.cpp
@@ -23,7 +23,7 @@
 #include <type_traits>
 #include <variant>
 
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "test_macros.h"
 
 void test_ctor_sfinae() {
diff --git a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_init_list_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_init_list_args.pass.cpp
index 179b663..eb8c7da 100644
--- a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_init_list_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_index_init_list_args.pass.cpp
@@ -23,7 +23,7 @@
 #include <type_traits>
 #include <variant>
 
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "test_macros.h"
 
 struct InitList {
diff --git a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_args.pass.cpp
index 430ddca..9716d05 100644
--- a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_args.pass.cpp
@@ -22,7 +22,7 @@
 #include <type_traits>
 #include <variant>
 
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "test_macros.h"
 
 void test_ctor_sfinae() {
diff --git a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_init_list_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_init_list_args.pass.cpp
index 46dab74..75baf15 100644
--- a/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_init_list_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.ctor/in_place_type_init_list_args.pass.cpp
@@ -23,7 +23,7 @@
 #include <type_traits>
 #include <variant>
 
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "test_macros.h"
 
 struct InitList {
diff --git a/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_args.pass.cpp
index 95f16ac..07a70e4 100644
--- a/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_args.pass.cpp
@@ -23,10 +23,10 @@
 #include <type_traits>
 #include <variant>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 template <class Var, size_t I, class... Args>
 constexpr auto test_emplace_exists_imp(int) -> decltype(
diff --git a/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_init_list_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_init_list_args.pass.cpp
index aee3c3f..2660451 100644
--- a/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_init_list_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.mod/emplace_index_init_list_args.pass.cpp
@@ -23,8 +23,8 @@
 #include <type_traits>
 #include <variant>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 #include "test_macros.h"
 
 struct InitList {
diff --git a/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_args.pass.cpp
index 929806a..9eaddcc 100644
--- a/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_args.pass.cpp
@@ -22,10 +22,10 @@
 #include <type_traits>
 #include <variant>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 template <class Var, class T, class... Args>
 constexpr auto test_emplace_exists_imp(int) -> decltype(
diff --git a/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_init_list_args.pass.cpp b/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_init_list_args.pass.cpp
index 9cb9674..5910e50 100644
--- a/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_init_list_args.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.mod/emplace_type_init_list_args.pass.cpp
@@ -23,8 +23,8 @@
 #include <type_traits>
 #include <variant>
 
-#include "archetypes.hpp"
-#include "test_convertible.hpp"
+#include "archetypes.h"
+#include "test_convertible.h"
 #include "test_macros.h"
 
 struct InitList {
diff --git a/test/std/utilities/variant/variant.variant/variant.status/index.pass.cpp b/test/std/utilities/variant/variant.variant/variant.status/index.pass.cpp
index 6d463ad..657f9a1 100644
--- a/test/std/utilities/variant/variant.variant/variant.status/index.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.status/index.pass.cpp
@@ -20,9 +20,9 @@
 #include <type_traits>
 #include <variant>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 
 int main(int, char**) {
diff --git a/test/std/utilities/variant/variant.variant/variant.status/valueless_by_exception.pass.cpp b/test/std/utilities/variant/variant.variant/variant.status/valueless_by_exception.pass.cpp
index 2cb730c..2cf1824 100644
--- a/test/std/utilities/variant/variant.variant/variant.status/valueless_by_exception.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.status/valueless_by_exception.pass.cpp
@@ -20,9 +20,9 @@
 #include <type_traits>
 #include <variant>
 
-#include "archetypes.hpp"
+#include "archetypes.h"
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 
 int main(int, char**) {
diff --git a/test/std/utilities/variant/variant.variant/variant.swap/swap.pass.cpp b/test/std/utilities/variant/variant.variant/variant.swap/swap.pass.cpp
index 8443f1e..2c95dfe 100644
--- a/test/std/utilities/variant/variant.variant/variant.swap/swap.pass.cpp
+++ b/test/std/utilities/variant/variant.variant/variant.swap/swap.pass.cpp
@@ -22,9 +22,9 @@
 #include <type_traits>
 #include <variant>
 
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 struct NotSwappable {};
 void swap(NotSwappable &, NotSwappable &) = delete;
diff --git a/test/std/utilities/variant/variant.variant/variant_array.fail.cpp b/test/std/utilities/variant/variant.variant/variant_array.fail.cpp
index ce79e9c..32ad7c3 100644
--- a/test/std/utilities/variant/variant.variant/variant_array.fail.cpp
+++ b/test/std/utilities/variant/variant.variant/variant_array.fail.cpp
@@ -20,8 +20,8 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
-#include "test_convertible.hpp"
+#include "variant_test_helpers.h"
+#include "test_convertible.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/variant/variant.variant/variant_empty.fail.cpp b/test/std/utilities/variant/variant.variant/variant_empty.fail.cpp
index 3b93cb0..7fb78d4 100644
--- a/test/std/utilities/variant/variant.variant/variant_empty.fail.cpp
+++ b/test/std/utilities/variant/variant.variant/variant_empty.fail.cpp
@@ -16,7 +16,7 @@
 #include <variant>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/variant/variant.variant/variant_reference.fail.cpp b/test/std/utilities/variant/variant.variant/variant_reference.fail.cpp
index 7c2c466..dd7f71e 100644
--- a/test/std/utilities/variant/variant.variant/variant_reference.fail.cpp
+++ b/test/std/utilities/variant/variant.variant/variant_reference.fail.cpp
@@ -16,7 +16,7 @@
 #include <variant>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/variant/variant.variant/variant_void.fail.cpp b/test/std/utilities/variant/variant.variant/variant_void.fail.cpp
index 27e9c39..7be8ac4 100644
--- a/test/std/utilities/variant/variant.variant/variant_void.fail.cpp
+++ b/test/std/utilities/variant/variant.variant/variant_void.fail.cpp
@@ -20,8 +20,8 @@
 #include <cassert>
 
 #include "test_macros.h"
-#include "variant_test_helpers.hpp"
-#include "test_convertible.hpp"
+#include "variant_test_helpers.h"
+#include "test_convertible.h"
 
 int main(int, char**)
 {
diff --git a/test/std/utilities/variant/variant.visit/visit.pass.cpp b/test/std/utilities/variant/variant.visit/visit.pass.cpp
index 11e26d0..5a57164 100644
--- a/test/std/utilities/variant/variant.visit/visit.pass.cpp
+++ b/test/std/utilities/variant/variant.visit/visit.pass.cpp
@@ -24,7 +24,7 @@
 
 #include "test_macros.h"
 #include "type_id.h"
-#include "variant_test_helpers.hpp"
+#include "variant_test_helpers.h"
 
 enum CallType : unsigned {
   CT_None,
diff --git a/test/support/archetypes.hpp b/test/support/archetypes.h
similarity index 98%
rename from test/support/archetypes.hpp
rename to test/support/archetypes.h
index a0ea7c3..880c85d 100644
--- a/test/support/archetypes.hpp
+++ b/test/support/archetypes.h
@@ -1,5 +1,5 @@
-#ifndef TEST_SUPPORT_ARCHETYPES_HPP
-#define TEST_SUPPORT_ARCHETYPES_HPP
+#ifndef TEST_SUPPORT_ARCHETYPES_H
+#define TEST_SUPPORT_ARCHETYPES_H
 
 #include <type_traits>
 #include <cassert>
@@ -390,4 +390,4 @@
 
 #endif // TEST_STD_VER >= 11
 
-#endif // TEST_SUPPORT_ARCHETYPES_HPP
+#endif // TEST_SUPPORT_ARCHETYPES_H
diff --git a/test/support/constexpr_char_traits.hpp b/test/support/constexpr_char_traits.h
similarity index 100%
rename from test/support/constexpr_char_traits.hpp
rename to test/support/constexpr_char_traits.h
diff --git a/test/support/container_debug_tests.hpp b/test/support/container_debug_tests.h
similarity index 100%
rename from test/support/container_debug_tests.hpp
rename to test/support/container_debug_tests.h
diff --git a/test/support/controlled_allocators.hpp b/test/support/controlled_allocators.h
similarity index 98%
rename from test/support/controlled_allocators.hpp
rename to test/support/controlled_allocators.h
index 63a4c40..b00f7fd 100644
--- a/test/support/controlled_allocators.hpp
+++ b/test/support/controlled_allocators.h
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_CONTROLLED_ALLOCATORS_HPP
-#define SUPPORT_CONTROLLED_ALLOCATORS_HPP
+#ifndef SUPPORT_CONTROLLED_ALLOCATORS_H
+#define SUPPORT_CONTROLLED_ALLOCATORS_H
 
 #include <memory>
 #include <type_traits>
@@ -498,4 +498,4 @@
 }
 
 
-#endif /* SUPPORT_CONTROLLED_ALLOCATORS_HPP */
+#endif /* SUPPORT_CONTROLLED_ALLOCATORS_H */
diff --git a/test/support/count_new.hpp b/test/support/count_new.h
similarity index 98%
rename from test/support/count_new.hpp
rename to test/support/count_new.h
index 5601c00..9313d02 100644
--- a/test/support/count_new.hpp
+++ b/test/support/count_new.h
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef COUNT_NEW_HPP
-#define COUNT_NEW_HPP
+#ifndef COUNT_NEW_H
+#define COUNT_NEW_H
 
 # include <cstdlib>
 # include <cassert>
@@ -482,4 +482,4 @@
     RequireAllocationGuard& operator=(RequireAllocationGuard const&);
 };
 
-#endif /* COUNT_NEW_HPP */
+#endif /* COUNT_NEW_H */
diff --git a/test/support/counting_predicates.hpp b/test/support/counting_predicates.h
similarity index 100%
rename from test/support/counting_predicates.hpp
rename to test/support/counting_predicates.h
diff --git a/test/support/filesystem_include.hpp b/test/support/filesystem_include.h
similarity index 68%
rename from test/support/filesystem_include.hpp
rename to test/support/filesystem_include.h
index 731532a..f5c1d97 100644
--- a/test/support/filesystem_include.hpp
+++ b/test/support/filesystem_include.h
@@ -1,5 +1,5 @@
-#ifndef TEST_SUPPORT_FILESYSTEM_INCLUDE_HPP
-#define TEST_SUPPORT_FILESYSTEM_INCLUDE_HPP
+#ifndef TEST_SUPPORT_FILESYSTEM_INCLUDE_H
+#define TEST_SUPPORT_FILESYSTEM_INCLUDE_H
 
 #include <filesystem>
 #include "test_macros.h"
diff --git a/test/support/filesystem_test_helper.hpp b/test/support/filesystem_test_helper.h
similarity index 98%
rename from test/support/filesystem_test_helper.hpp
rename to test/support/filesystem_test_helper.h
index 467abd5..8cefd98 100644
--- a/test/support/filesystem_test_helper.hpp
+++ b/test/support/filesystem_test_helper.h
@@ -1,7 +1,7 @@
-#ifndef FILESYSTEM_TEST_HELPER_HPP
-#define FILESYSTEM_TEST_HELPER_HPP
+#ifndef FILESYSTEM_TEST_HELPER_H
+#define FILESYSTEM_TEST_HELPER_H
 
-#include "filesystem_include.hpp"
+#include "filesystem_include.h"
 
 #include <unistd.h> // for ftruncate
 
@@ -15,8 +15,8 @@
 #include <regex>
 
 #include "test_macros.h"
-#include "rapid-cxx-test.hpp"
-#include "format_string.hpp"
+#include "rapid-cxx-test.h"
+#include "format_string.h"
 
 // static test helpers
 
diff --git a/test/support/format_string.hpp b/test/support/format_string.h
similarity index 95%
rename from test/support/format_string.hpp
rename to test/support/format_string.h
index 44dc30f..e330164 100644
--- a/test/support/format_string.hpp
+++ b/test/support/format_string.h
@@ -1,5 +1,5 @@
-#ifndef TEST_SUPPORT_FORMAT_STRING_HPP
-#define TEST_SUPPORT_FORMAT_STRING_HPP
+#ifndef TEST_SUPPORT_FORMAT_STRING_H
+#define TEST_SUPPORT_FORMAT_STRING_H
 
 #include <cstdio>
 #include <string>
diff --git a/test/support/msvc_stdlib_force_include.hpp b/test/support/msvc_stdlib_force_include.h
similarity index 95%
rename from test/support/msvc_stdlib_force_include.hpp
rename to test/support/msvc_stdlib_force_include.h
index fd8438f..83920d5 100644
--- a/test/support/msvc_stdlib_force_include.hpp
+++ b/test/support/msvc_stdlib_force_include.h
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_HPP
-#define SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_HPP
+#ifndef SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_H
+#define SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_H
 
 // This header is force-included when running the libc++ tests against the
 // MSVC standard library.
@@ -89,4 +89,4 @@
 
 #define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
 
-#endif // SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_HPP
+#endif // SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_H
diff --git a/test/support/nasty_containers.hpp b/test/support/nasty_containers.h
similarity index 100%
rename from test/support/nasty_containers.hpp
rename to test/support/nasty_containers.h
diff --git a/test/support/nasty_macros.hpp b/test/support/nasty_macros.h
similarity index 94%
rename from test/support/nasty_macros.hpp
rename to test/support/nasty_macros.h
index 0106f70..d69bc4b 100644
--- a/test/support/nasty_macros.hpp
+++ b/test/support/nasty_macros.h
@@ -5,8 +5,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-#ifndef SUPPORT_NASTY_MACROS_HPP
-#define SUPPORT_NASTY_MACROS_HPP
+#ifndef SUPPORT_NASTY_MACROS_H
+#define SUPPORT_NASTY_MACROS_H
 
 #define NASTY_MACRO This should not be expanded!!!
 #define _A NASTY_MACRO
@@ -65,4 +65,4 @@
 #define __acquire NASTY_MACRO
 #define __release NASTY_MACRO
 
-#endif // SUPPORT_NASTY_MACROS_HPP
+#endif // SUPPORT_NASTY_MACROS_H
diff --git a/test/support/poisoned_hash_helper.hpp b/test/support/poisoned_hash_helper.h
similarity index 97%
rename from test/support/poisoned_hash_helper.hpp
rename to test/support/poisoned_hash_helper.h
index 83687dd..60ce6f9 100644
--- a/test/support/poisoned_hash_helper.hpp
+++ b/test/support/poisoned_hash_helper.h
@@ -6,8 +6,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-#ifndef SUPPORT_POISONED_HASH_HELPER_HPP
-#define SUPPORT_POISONED_HASH_HELPER_HPP
+#ifndef SUPPORT_POISONED_HASH_HELPER_H
+#define SUPPORT_POISONED_HASH_HELPER_H
 
 #include <type_traits>
 #include <cassert>
@@ -239,4 +239,4 @@
   Types::template applyTrait<TestLibraryTrait >();
 }
 
-#endif // SUPPORT_POISONED_HASH_HELPER_HPP
+#endif // SUPPORT_POISONED_HASH_HELPER_H
diff --git a/test/support/private_constructor.hpp b/test/support/private_constructor.h
similarity index 100%
rename from test/support/private_constructor.hpp
rename to test/support/private_constructor.h
diff --git a/test/support/rapid-cxx-test.hpp b/test/support/rapid-cxx-test.h
similarity index 99%
rename from test/support/rapid-cxx-test.hpp
rename to test/support/rapid-cxx-test.h
index bf02740..0f3dcd8 100644
--- a/test/support/rapid-cxx-test.hpp
+++ b/test/support/rapid-cxx-test.h
@@ -1,5 +1,5 @@
-#ifndef RAPID_CXX_TEST_HPP
-#define RAPID_CXX_TEST_HPP
+#ifndef RAPID_CXX_TEST_H
+#define RAPID_CXX_TEST_H
 
 # include <cstddef>
 # include <cstdlib>
@@ -863,4 +863,4 @@
 #   pragma GCC diagnostic pop
 # endif
 
-#endif /* RAPID_CXX_TEST_HPP */
+#endif /* RAPID_CXX_TEST_H */
diff --git a/test/support/test.support/test_convertible_header.pass.cpp b/test/support/test.support/test_convertible_header.pass.cpp
index fafa966..5280dfd 100644
--- a/test/support/test.support/test_convertible_header.pass.cpp
+++ b/test/support/test.support/test_convertible_header.pass.cpp
@@ -8,9 +8,9 @@
 
 // UNSUPPORTED: c++98, c++03
 
-// "support/test_convertible.hpp"
+// "support/test_convertible.h"
 
-#include "test_convertible.hpp"
+#include "test_convertible.h"
 
 #include "test_macros.h"
 
diff --git a/test/support/test.support/test_poisoned_hash_helper.pass.cpp b/test/support/test.support/test_poisoned_hash_helper.pass.cpp
index 8c4d39e..c642f0c 100644
--- a/test/support/test.support/test_poisoned_hash_helper.pass.cpp
+++ b/test/support/test.support/test_poisoned_hash_helper.pass.cpp
@@ -8,12 +8,12 @@
 
 // UNSUPPORTED: c++98, c++03
 
-// Test that the header `poisoned_hash_helper.hpp` doesn't include any
+// Test that the header `poisoned_hash_helper.h` doesn't include any
 // headers that provide hash<T> specializations. This is required so that the
 // 'test_library_hash_specializations_available()' function returns false
 // by default, unless a STL header providing hash has already been included.
 
-#include "poisoned_hash_helper.hpp"
+#include "poisoned_hash_helper.h"
 
 #include "test_macros.h"
 
diff --git a/test/support/test_convertible.hpp b/test/support/test_convertible.h
similarity index 87%
rename from test/support/test_convertible.hpp
rename to test/support/test_convertible.h
index 322ef50..becbb2b 100644
--- a/test/support/test_convertible.hpp
+++ b/test/support/test_convertible.h
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_TEST_CONVERTIBLE_HPP
-#define SUPPORT_TEST_CONVERTIBLE_HPP
+#ifndef SUPPORT_TEST_CONVERTIBLE_H
+#define SUPPORT_TEST_CONVERTIBLE_H
 
 // "test_convertible<Tp, Args...>()" is a metafunction used to check if 'Tp'
 // is implicitly convertible from 'Args...' for any number of arguments,
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 
 #if TEST_STD_VER < 11
-#error test_convertible.hpp requires C++11 or newer
+#error test_convertible.h requires C++11 or newer
 #endif
 
 namespace detail {
@@ -38,4 +38,4 @@
 constexpr bool test_convertible()
 { return detail::test_convertible_imp<Tp, Args...>(0); }
 
-#endif // SUPPORT_TEST_CONVERTIBLE_HPP
+#endif // SUPPORT_TEST_CONVERTIBLE_H
diff --git a/test/support/test_memory_resource.hpp b/test/support/test_memory_resource.h
similarity index 95%
rename from test/support/test_memory_resource.hpp
rename to test/support/test_memory_resource.h
index 0483f3b..1a0d722 100644
--- a/test/support/test_memory_resource.hpp
+++ b/test/support/test_memory_resource.h
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_TEST_MEMORY_RESOURCE_HPP
-#define SUPPORT_TEST_MEMORY_RESOURCE_HPP
+#ifndef SUPPORT_TEST_MEMORY_RESOURCE_H
+#define SUPPORT_TEST_MEMORY_RESOURCE_H
 
 #include <experimental/memory_resource>
 #include <experimental/utility>
@@ -19,8 +19,8 @@
 #include <cstdint>
 #include <cassert>
 #include "test_macros.h"
-#include "controlled_allocators.hpp"
-#include "uses_alloc_types.hpp"
+#include "controlled_allocators.h"
+#include "uses_alloc_types.h"
 
 // FIXME: This is a hack to allow uses_allocator_types.hpp to work with
 // erased_type. However we can't define that behavior directly in the header
@@ -167,4 +167,4 @@
 using TestResource2 = TestResourceImp<BufferProvider<>, 2>;
 
 
-#endif /* SUPPORT_TEST_MEMORY_RESOURCE_HPP */
+#endif /* SUPPORT_TEST_MEMORY_RESOURCE_H */
diff --git a/test/support/user_defined_integral.hpp b/test/support/user_defined_integral.h
similarity index 91%
rename from test/support/user_defined_integral.hpp
rename to test/support/user_defined_integral.h
index a313fe6..e3d5724 100644
--- a/test/support/user_defined_integral.hpp
+++ b/test/support/user_defined_integral.h
@@ -5,8 +5,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-#ifndef SUPPORT_USER_DEFINED_INTEGRAL_HPP
-#define SUPPORT_USER_DEFINED_INTEGRAL_HPP
+#ifndef SUPPORT_USER_DEFINED_INTEGRAL_H
+#define SUPPORT_USER_DEFINED_INTEGRAL_H
 
 template <class T>
 struct UserDefinedIntegral
@@ -48,4 +48,4 @@
 template <class T, class U>
 void operator>=(UserDefinedIntegral<T>, UserDefinedIntegral<U>);
 
-#endif // SUPPORT_USER_DEFINED_INTEGRAL_HPP
+#endif // SUPPORT_USER_DEFINED_INTEGRAL_H
diff --git a/test/support/uses_alloc_types.hpp b/test/support/uses_alloc_types.h
similarity index 98%
rename from test/support/uses_alloc_types.hpp
rename to test/support/uses_alloc_types.h
index 4b1a95d..c3bbd72 100644
--- a/test/support/uses_alloc_types.hpp
+++ b/test/support/uses_alloc_types.h
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef USES_ALLOC_TYPES_HPP
-#define USES_ALLOC_TYPES_HPP
+#ifndef USES_ALLOC_TYPES_H
+#define USES_ALLOC_TYPES_H
 
 # include <memory>
 # include <cassert>
@@ -142,7 +142,7 @@
 // polymorphic allocators. However we don't want to include
 // <experimental/memory_resource> in this header. Therefore in order
 // to inject this behavior later we use a trait.
-// See test_memory_resource.hpp for more info.
+// See test_memory_resource.h for more info.
 template <class Alloc>
 struct TransformErasedTypeAlloc {
   using type = Alloc;
@@ -387,4 +387,4 @@
     {}
 };
 
-#endif /* USES_ALLOC_TYPES_HPP */
+#endif /* USES_ALLOC_TYPES_H */
diff --git a/test/support/variant_test_helpers.hpp b/test/support/variant_test_helpers.h
similarity index 94%
rename from test/support/variant_test_helpers.hpp
rename to test/support/variant_test_helpers.h
index 9d4ceec..0e04093 100644
--- a/test/support/variant_test_helpers.hpp
+++ b/test/support/variant_test_helpers.h
@@ -6,8 +6,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-#ifndef SUPPORT_VARIANT_TEST_HELPERS_HPP
-#define SUPPORT_VARIANT_TEST_HELPERS_HPP
+#ifndef SUPPORT_VARIANT_TEST_HELPERS_H
+#define SUPPORT_VARIANT_TEST_HELPERS_H
 
 #include <type_traits>
 #include <utility>
@@ -86,4 +86,4 @@
 #endif // TEST_HAS_NO_EXCEPTIONS
 
 
-#endif // SUPPORT_VARIANT_TEST_HELPERS_HPP
+#endif // SUPPORT_VARIANT_TEST_HELPERS_H
diff --git a/utils/libcxx/test/config.py b/utils/libcxx/test/config.py
index 641bd4a..f353432 100644
--- a/utils/libcxx/test/config.py
+++ b/utils/libcxx/test/config.py
@@ -602,11 +602,11 @@
         if self.cxx_stdlib_under_test != 'libstdc++' and \
            not self.is_windows:
             self.cxx.compile_flags += [
-                '-include', os.path.join(support_path, 'nasty_macros.hpp')]
+                '-include', os.path.join(support_path, 'nasty_macros.h')]
         if self.cxx_stdlib_under_test == 'msvc':
             self.cxx.compile_flags += [
                 '-include', os.path.join(support_path,
-                                         'msvc_stdlib_force_include.hpp')]
+                                         'msvc_stdlib_force_include.h')]
             pass
         if self.is_windows and self.debug_build and \
                 self.cxx_stdlib_under_test != 'msvc':