--- boost/config/stdlib/libcpp.hpp.orig
+++ boost/config/stdlib/libcpp.hpp
@@ -15,6 +15,10 @@
 #  endif
 #endif
 
+#if defined(__APPLE__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1070
+#  define BOOST_NO_CXX11_THREAD_LOCAL
+#endif
+
 #define BOOST_STDLIB "libc++ version " BOOST_STRINGIZE(_LIBCPP_VERSION)
 
 #define BOOST_HAS_THREADS