diff --git a/include/boost/config/stdlib/libcpp.hpp b/include/boost/config/stdlib/libcpp.hpp
index 66642e72..c32eddf4 100644
--- a/include/boost/config/stdlib/libcpp.hpp
+++ b/include/boost/config/stdlib/libcpp.hpp
@@ -53,9 +53,9 @@
 #  define BOOST_NO_CXX11_HDR_FUNCTIONAL
 #  define BOOST_NO_CXX11_STD_ALIGN
 #  define BOOST_NO_CXX11_ADDRESSOF
-#  if _LIBCPP_VERSION < 3700
-#    define BOOST_NO_CXX11_HDR_ATOMIC
-#  endif
+#  define BOOST_NO_CXX11_HDR_ATOMIC
+#elif _LIBCPP_VERSION < 3700
+#  define BOOST_NO_CXX11_HDR_ATOMIC
 #endif
 
 //