diff --git a/test/std/strings/basic.string/string.access/back.pass.cpp b/test/std/strings/basic.string/string.access/back.pass.cpp
index dd2a59a..69b88cc 100644
--- a/test/std/strings/basic.string/string.access/back.pass.cpp
+++ b/test/std/strings/basic.string/string.access/back.pass.cpp
@@ -52,7 +52,7 @@
 #ifdef _LIBCPP_DEBUG
     {
         std::string s;
-        char c = s.back();
+        (void) s.back();
         assert(false);
     }
 #endif
diff --git a/test/std/strings/basic.string/string.access/front.pass.cpp b/test/std/strings/basic.string/string.access/front.pass.cpp
index b666c9c..c1ce626 100644
--- a/test/std/strings/basic.string/string.access/front.pass.cpp
+++ b/test/std/strings/basic.string/string.access/front.pass.cpp
@@ -52,7 +52,7 @@
 #ifdef _LIBCPP_DEBUG
     {
         std::string s;
-        char c = s.front();
+        (void) s.front();
         assert(false);
     }
 #endif
diff --git a/test/std/strings/basic.string/string.iterators/db_iterators_2.pass.cpp b/test/std/strings/basic.string/string.iterators/db_iterators_2.pass.cpp
index 4696323..0b49626 100644
--- a/test/std/strings/basic.string/string.iterators/db_iterators_2.pass.cpp
+++ b/test/std/strings/basic.string/string.iterators/db_iterators_2.pass.cpp
@@ -29,6 +29,7 @@
     S s1;
     S s2;
     bool b = s1.begin() < s2.begin();
+    (void) b;
     assert(false);
     }
 #if TEST_STD_VER >= 11
@@ -37,6 +38,7 @@
     S s1;
     S s2;
     bool b = s1.begin() < s2.begin();
+    (void) b;
     assert(false);
     }
 #endif
diff --git a/test/std/strings/basic.string/string.iterators/db_iterators_3.pass.cpp b/test/std/strings/basic.string/string.iterators/db_iterators_3.pass.cpp
index 7dbbbbb..0782461 100644
--- a/test/std/strings/basic.string/string.iterators/db_iterators_3.pass.cpp
+++ b/test/std/strings/basic.string/string.iterators/db_iterators_3.pass.cpp
@@ -29,6 +29,7 @@
     S s1;
     S s2;
     int i = s1.begin() - s2.begin();
+    (void) i;
     assert(false);
     }
 #if TEST_STD_VER >= 11
@@ -37,6 +38,7 @@
     S s1;
     S s2;
     int i = s1.begin() - s2.begin();
+    (void) i;
     assert(false);
     }
 #endif
diff --git a/test/std/strings/basic.string/string.iterators/db_iterators_8.pass.cpp b/test/std/strings/basic.string/string.iterators/db_iterators_8.pass.cpp
index c69f8ca..0420f5e 100644
--- a/test/std/strings/basic.string/string.iterators/db_iterators_8.pass.cpp
+++ b/test/std/strings/basic.string/string.iterators/db_iterators_8.pass.cpp
@@ -28,7 +28,7 @@
     typedef std::string C;
     C c(1, '\0');
     C::iterator i = c.end();
-    char j = *i;
+    (void) *i;
     assert(false);
     }
 #if TEST_STD_VER >= 11
@@ -36,7 +36,7 @@
     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> C;
     C c(1, '\0');
     C::iterator i = c.end();
-    char j = *i;
+    (void) *i;
     assert(false);
     }
 #endif