Index: boost/lockfree/detail/atomic.hpp
===================================================================
--- boost/lockfree/detail/atomic.hpp	(revision 84380)
+++ boost/lockfree/detail/atomic.hpp	(working copy)
@@ -17,6 +17,13 @@
 #undef BOOST_LOCKFREE_NO_HDR_ATOMIC
 #endif
 
+// Clang / libc++ supports atomic<> 3.1 onwards, but check for <atomic> to make sure
+#if defined(BOOST_CLANG)
+#if defined(_LIBCPP_VERSION) && __has_include( <atomic> )
+#undef BOOST_LOCKFREE_NO_HDR_ATOMIC
+#endif
+#endif
+
 // GCC supports atomic<> from version 4.8 onwards.
 #if defined(__GNUC__)
 # if defined(__GNUC_PATCHLEVEL__)