Index: include/type_traits
===================================================================
--- include/type_traits
+++ include/type_traits
@@ -1347,10 +1347,9 @@
 
 template <class _From, class _To>
 struct __is_convertible_test<_From, _To,
-    decltype(__test_convert<_To>(_VSTD::declval<_From>()))> : public true_type
+    decltype(_VSTD::__is_convertible_imp::__test_convert<_To>(_VSTD::declval<_From>()))> : public true_type
 {};
 
-template <class _Tp> __two __test(...);
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _Tp> _Tp&& __source();
 #else
Index: test/std/utilities/meta/meta.rel/is_convertible.pass.cpp
===================================================================
--- test/std/utilities/meta/meta.rel/is_convertible.pass.cpp
+++ test/std/utilities/meta/meta.rel/is_convertible.pass.cpp
@@ -52,6 +52,11 @@
   NonCopyable(NonCopyable&);
 };
 
+template <typename T>
+class CannotInstantiate {
+  enum { X = T::ThisExpressionWillBlowUp };
+};
+
 int main()
 {
     // void
@@ -206,4 +211,7 @@
     test_is_not_convertible<NonCopyable&, NonCopyable>();
 #endif
 
+    // Ensure that CannotInstantiate is not instantiated by is_convertible when it is not needed.
+    // For example CannotInstantiate is instatiated as a part of ADL lookup for arguments of type CannotInstantiate*.
+    static_assert((std::is_convertible<CannotInstantiate<int>*, CannotInstantiate<int>*>::value), "");
 }