diff --git a/test/optional_xconfig_HACK_TO_LIST_PREDEFINED_MACROS.cpp b/test/optional_xconfig_HACK_TO_LIST_PREDEFINED_MACROS.cpp
index aa21cf5..f8cf269 100644
--- a/test/optional_xconfig_HACK_TO_LIST_PREDEFINED_MACROS.cpp
+++ b/test/optional_xconfig_HACK_TO_LIST_PREDEFINED_MACROS.cpp
@@ -40,6 +40,7 @@ int main()
 #endif
 
   BOOST_TEST_EQ(empty, BOOST_COMP_GNUC);
+  BOOST_TEST_EQ(empty, BOOST_COMP_CLANG);
   BOOST_TEST_EQ(empty, BOOST_LANG_STDCPP);
   BOOST_TEST_EQ(empty, BOOST_LIB_C_GNU);
   BOOST_TEST_EQ(empty, BOOST_LIB_STD_CXX);