diff --git a/include/boost/mp11/detail/config.hpp b/include/boost/mp11/detail/config.hpp
index 0a9ded5..764bd59 100644
--- a/include/boost/mp11/detail/config.hpp
+++ b/include/boost/mp11/detail/config.hpp
@@ -47,7 +47,9 @@
 
 # endif
 
-#elif defined(__clang__)
+#endif
+
+#if defined(__clang__)
 
 // Clang