diff --git a/include/__tree b/include/__tree
index bfcec78..b560bf0 100644
--- a/include/__tree
+++ b/include/__tree
@@ -1419,7 +1419,11 @@
 
     _LIBCPP_INLINE_VISIBILITY
     void __copy_assign_alloc(const __tree& __t, true_type)
-        {__node_alloc() = __t.__node_alloc();}
+        {
+        if (__node_alloc() != __t.__node_alloc())
+        	clear();
+        __node_alloc() = __t.__node_alloc();
+        }
     _LIBCPP_INLINE_VISIBILITY
     void __copy_assign_alloc(const __tree& __t, false_type) {}
 
diff --git a/test/std/containers/associative/map/map.cons/copy_assign.pass.cpp b/test/std/containers/associative/map/map.cons/copy_assign.pass.cpp
index fc6641a..cc5d0d5 100644
--- a/test/std/containers/associative/map/map.cons/copy_assign.pass.cpp
+++ b/test/std/containers/associative/map/map.cons/copy_assign.pass.cpp
@@ -15,11 +15,99 @@
 
 #include <map>
 #include <cassert>
+#include <vector>
+#include <algorithm>
+
+#include <iostream>
 
 #include "../../../test_compare.h"
 #include "test_allocator.h"
 #include "min_allocator.h"
 
+#if TEST_STD_VER >= 11
+std::vector<int> ca_allocs;
+std::vector<int> ca_deallocs;
+
+template <class T>
+class counting_allocatorT {
+public:
+    typedef T value_type;
+    int foo{0};
+    counting_allocatorT(int f) noexcept : foo(f) {}
+
+    using propagate_on_container_copy_assignment = std::true_type;    
+    template <class U> counting_allocatorT(const counting_allocatorT<U>& other) noexcept {foo = other.foo;}
+    template <class U> bool operator==(const counting_allocatorT<U>& other) const noexcept { return foo == other.foo; }
+    template <class U> bool operator!=(const counting_allocatorT<U>& other) const noexcept { return foo != other.foo; }
+
+    T * allocate(const size_t n) const {
+        ca_allocs.push_back(foo);
+        void * const pv = ::malloc(n * sizeof(T));
+        return static_cast<T *>(pv);
+    }
+    void deallocate(T * const p, size_t) const noexcept {
+        ca_deallocs.push_back(foo);
+        free(p);
+    }
+};
+
+template <class T>
+class counting_allocatorF {
+public:
+    typedef T value_type;
+    int foo{0};
+    counting_allocatorF(int f) noexcept : foo(f) {}
+
+    using propagate_on_container_copy_assignment = std::false_type;    
+    template <class U> counting_allocatorF(const counting_allocatorF<U>& other) noexcept {foo = other.foo;}
+    template <class U> bool operator==(const counting_allocatorF<U>& other) const noexcept { return foo == other.foo; }
+    template <class U> bool operator!=(const counting_allocatorF<U>& other) const noexcept { return foo != other.foo; }
+
+    T * allocate(const size_t n) const {
+        ca_allocs.push_back(foo);
+        void * const pv = ::malloc(n * sizeof(T));
+        return static_cast<T *>(pv);
+    }
+    void deallocate(T * const p, size_t) const noexcept {
+        ca_deallocs.push_back(foo);
+        free(p);
+    }
+};
+
+bool balanced_allocs() {
+    std::vector<int> temp1, temp2;
+    
+    std::cout << "Allocations = " << ca_allocs.size() << ", deallocatons = " << ca_deallocs.size() << std::endl;
+    if (ca_allocs.size() != ca_deallocs.size())
+        return false;
+
+    temp1 = ca_allocs;
+    std::sort(temp1.begin(), temp1.end());
+    temp2.clear();
+    std::unique_copy(temp1.begin(), temp1.end(), std::back_inserter<std::vector<int>>(temp2));
+    std::cout << "There were " << temp2.size() << " different allocators\n";
+    
+    for (std::vector<int>::const_iterator it = temp2.begin(); it != temp2.end(); ++it ) {
+        std::cout << *it << ": " << std::count(ca_allocs.begin(), ca_allocs.end(), *it) << " vs " << std::count(ca_deallocs.begin(), ca_deallocs.end(), *it) << std::endl;
+        if ( std::count(ca_allocs.begin(), ca_allocs.end(), *it) != std::count(ca_deallocs.begin(), ca_deallocs.end(), *it))
+            return false;
+        }
+        
+    temp1 = ca_allocs;
+    std::sort(temp1.begin(), temp1.end());
+    temp2.clear();
+    std::unique_copy(temp1.begin(), temp1.end(), std::back_inserter<std::vector<int>>(temp2));
+    std::cout << "There were " << temp2.size() << " different (de)allocators\n";
+    for (std::vector<int>::const_iterator it = ca_deallocs.begin(); it != ca_deallocs.end(); ++it ) {
+        std::cout << *it << ": " << std::count(ca_allocs.begin(), ca_allocs.end(), *it) << " vs " << std::count(ca_deallocs.begin(), ca_deallocs.end(), *it) << std::endl;
+        if ( std::count(ca_allocs.begin(), ca_allocs.end(), *it) != std::count(ca_deallocs.begin(), ca_deallocs.end(), *it))
+            return false;
+        }
+    
+    return true;
+    }
+#endif
+
 int main()
 {
     {
@@ -178,5 +266,75 @@
         assert(*next(mo.begin()) == V(2, 1));
         assert(*next(mo.begin(), 2) == V(3, 1));
     }
+
+    assert(balanced_allocs());
+    {
+        typedef std::pair<const int, double> V;
+        V ar[] =
+        {
+            V(1, 1),
+            V(1, 1.5),
+            V(1, 2),
+            V(2, 1),
+            V(2, 1.5),
+            V(2, 2),
+            V(3, 1),
+            V(3, 1.5),
+            V(3, 2)
+        };
+        typedef test_compare<std::less<int> > C;
+        typedef counting_allocatorT<V> A;
+        std::map<int, double, C, A> mo(ar, ar+sizeof(ar)/sizeof(ar[0]), C(5), A(1));
+        std::map<int, double, C, A> m(ar, ar+sizeof(ar)/sizeof(ar[0])/2, C(3), A(2));
+        m = mo;
+        assert(m.key_comp() == C(5));
+        assert(m.size() == 3);
+        assert(distance(m.begin(), m.end()) == 3);
+        assert(*m.begin() == V(1, 1));
+        assert(*next(m.begin()) == V(2, 1));
+        assert(*next(m.begin(), 2) == V(3, 1));
+
+        assert(mo.key_comp() == C(5));
+        assert(mo.size() == 3);
+        assert(distance(mo.begin(), mo.end()) == 3);
+        assert(*mo.begin() == V(1, 1));
+        assert(*next(mo.begin()) == V(2, 1));
+        assert(*next(mo.begin(), 2) == V(3, 1));
+    }
+    assert(balanced_allocs());
+    {
+        typedef std::pair<const int, double> V;
+        V ar[] =
+        {
+            V(1, 1),
+            V(1, 1.5),
+            V(1, 2),
+            V(2, 1),
+            V(2, 1.5),
+            V(2, 2),
+            V(3, 1),
+            V(3, 1.5),
+            V(3, 2)
+        };
+        typedef test_compare<std::less<int> > C;
+        typedef counting_allocatorF<V> A;
+        std::map<int, double, C, A> mo(ar, ar+sizeof(ar)/sizeof(ar[0]), C(5), A(100));
+        std::map<int, double, C, A> m(ar, ar+sizeof(ar)/sizeof(ar[0])/2, C(3), A(200));
+        m = mo;
+        assert(m.key_comp() == C(5));
+        assert(m.size() == 3);
+        assert(distance(m.begin(), m.end()) == 3);
+        assert(*m.begin() == V(1, 1));
+        assert(*next(m.begin()) == V(2, 1));
+        assert(*next(m.begin(), 2) == V(3, 1));
+
+        assert(mo.key_comp() == C(5));
+        assert(mo.size() == 3);
+        assert(distance(mo.begin(), mo.end()) == 3);
+        assert(*mo.begin() == V(1, 1));
+        assert(*next(mo.begin()) == V(2, 1));
+        assert(*next(mo.begin(), 2) == V(3, 1));
+    }
+    assert(balanced_allocs());
 #endif
 }