diff --git a/include/string b/include/string
index e6d1614..611e345 100644
--- a/include/string
+++ b/include/string
@@ -862,10 +862,10 @@
         _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
         explicit basic_string(const _Tp& __t, const allocator_type& __a);
 
-    template<class _InputIterator>
+    template<class _InputIterator, class = typename enable_if<__is_input_iterator<_InputIterator>::value>::type>
         _LIBCPP_INLINE_VISIBILITY
         basic_string(_InputIterator __first, _InputIterator __last);
-    template<class _InputIterator>
+    template<class _InputIterator, class = typename enable_if<__is_input_iterator<_InputIterator>::value>::type>
         _LIBCPP_INLINE_VISIBILITY
         basic_string(_InputIterator __first, _InputIterator __last, const allocator_type& __a);
 #ifndef _LIBCPP_CXX03_LANG
@@ -2077,7 +2077,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-template<class _InputIterator>
+template<class _InputIterator, class>
 inline
 basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last)
 {
@@ -2088,7 +2088,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-template<class _InputIterator>
+template<class _InputIterator, class>
 inline
 basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last,
                                                         const allocator_type& __a)
diff --git a/test/std/strings/basic.string/string.cons/iter_alloc.pass.cpp b/test/std/strings/basic.string/string.cons/iter_alloc.pass.cpp
index 042018c..8850dd2 100644
--- a/test/std/strings/basic.string/string.cons/iter_alloc.pass.cpp
+++ b/test/std/strings/basic.string/string.cons/iter_alloc.pass.cpp
@@ -116,6 +116,15 @@
     test(input_iterator<const char*>(s), input_iterator<const char*>(s+50), A());
     }
 #endif
+    {
+      static_assert((!std::is_constructible<std::string, std::string,
+                                            std::string>::value),
+                    "");
+      static_assert(
+          (!std::is_constructible<std::string, std::string, std::string,
+                                  std::allocator<char> >::value),
+          "");
+    }
 
   return 0;
 }