diff --git a/include/boost/intrusive/detail/std_fwd.hpp b/include/boost/intrusive/detail/std_fwd.hpp
index 0492c1d..4b5cedb 100644
--- a/include/boost/intrusive/detail/std_fwd.hpp
+++ b/include/boost/intrusive/detail/std_fwd.hpp
@@ -23,10 +23,12 @@
 //                        Standard predeclarations
 //////////////////////////////////////////////////////////////////////////////
 
-#if defined(__clang__) && defined(_LIBCPP_VERSION)
+#if defined(_LIBCPP_VERSION)
    #define BOOST_INTRUSIVE_CLANG_INLINE_STD_NS
    #pragma GCC diagnostic push
-   #pragma GCC diagnostic ignored "-Wc++11-extensions"
+   #if defined(__clang__)
+      #pragma GCC diagnostic ignored "-Wc++11-extensions"
+   #endif
    #define BOOST_INTRUSIVE_STD_NS_BEG _LIBCPP_BEGIN_NAMESPACE_STD
    #define BOOST_INTRUSIVE_STD_NS_END _LIBCPP_END_NAMESPACE_STD
 #elif defined(BOOST_GNU_STDLIB) && defined(_GLIBCXX_BEGIN_NAMESPACE_VERSION)  //GCC >= 4.6