diff --git a/.drone.star b/.drone.star
index 69856757..d841da98 100644
--- a/.drone.star
+++ b/.drone.star
@@ -45,6 +45,7 @@ def main(ctx):
   linux_cxx("clang++-10 03,11,14,17,20", "clang++-10", packages="clang-10", llvm_os="xenial", llvm_ver="10", buildtype="boost", image="cppalliance/droneubuntu1804:1", environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-10', 'CXXSTD': '03,11,14,17,20', }, globalenv=globalenv),
   osx_cxx("XCode-11.7 03,11,17,2a", "clang++", packages="", buildtype="boost", xcode_version="11.7", environment={'TOOLSET': 'clang', 'COMPILER': 'clang++', 'CXXSTD': '03,11,14,17,2a', }, globalenv=globalenv),
   osx_cxx("XCode-10.2 03,11,17,2a", "clang++", packages="", buildtype="boost", xcode_version="10.2", environment={'TOOLSET': 'clang', 'COMPILER': 'clang++', 'CXXSTD': '03,11,14,17,2a', }, globalenv=globalenv),
+  osx_cxx("XCode-9.4.1 03,11,14", "clang++", packages="", buildtype="boost", xcode_version="9.4.1", environment={'TOOLSET': 'clang', 'COMPILER': 'clang++', 'CXXSTD': '03,11,14', }, globalenv=globalenv),
   ]
 
 # from https://github.com/boostorg/boost-ci
diff --git a/include/boost/config/stdlib/libstdcpp3.hpp b/include/boost/config/stdlib/libstdcpp3.hpp
index 5a9f444e..ad70936d 100644
--- a/include/boost/config/stdlib/libstdcpp3.hpp
+++ b/include/boost/config/stdlib/libstdcpp3.hpp
@@ -439,6 +439,13 @@ extern "C" char *gets (char *__s);
 #endif
 #endif
 
+#if defined(__clang__) && (BOOST_LIBSTDCXX_VERSION < 40300) && !defined(BOOST_NO_CXX11_NULLPTR)
+#  define BOOST_NO_CXX11_NULLPTR
+#endif
+#if defined(__clang__) && (BOOST_LIBSTDCXX_VERSION < 40300) && defined(BOOST_HAS_INT128) && defined(__APPLE_CC__)
+#undef BOOST_HAS_INT128
+#endif
+
 //
 // Headers not present on Solaris with the Oracle compiler:
 #if defined(__SUNPRO_CC) && (__SUNPRO_CC < 0x5140)