diff --git a/libcxx/include/experimental/type_traits b/libcxx/include/experimental/type_traits
--- a/libcxx/include/experimental/type_traits
+++ b/libcxx/include/experimental/type_traits
@@ -18,7 +18,7 @@
 
 namespace std {
 namespace experimental {
-inline namespace fundamentals_v1 {
+inline namespace fundamentals_v2 {
 
   // 3.3.2, Other type transformations
   template <class> class invocation_type; // not defined
@@ -62,7 +62,7 @@
      constexpr bool is_detected_convertible_v
        = is_detected_convertible<To, Op, Args...>::value;
 
-} // namespace fundamentals_v1
+} // namespace fundamentals_v2
 } // namespace experimental
 } // namespace std
 
@@ -79,7 +79,7 @@
 #pragma GCC system_header
 #endif
 
-_LIBCPP_BEGIN_NAMESPACE_LFTS
+_LIBCPP_BEGIN_NAMESPACE_LFTS_V2
 
 // 3.3.2, Other type transformations
 /*
@@ -147,7 +147,7 @@
   _LIBCPP_CONSTEXPR bool is_detected_convertible_v = is_detected_convertible<To, _Op, _Args...>::value;
 
 
-_LIBCPP_END_NAMESPACE_LFTS
+_LIBCPP_END_NAMESPACE_LFTS_V2
 
 #endif /* _LIBCPP_STD_VER > 11 */