diff --git a/include/boost/core/bit.hpp b/include/boost/core/bit.hpp
index 5d24045..cebc878 100644
--- a/include/boost/core/bit.hpp
+++ b/include/boost/core/bit.hpp
@@ -56,7 +56,7 @@
 #  define BOOST_CORE_HAS_BUILTIN_BIT_CAST
 #endif
 
-#if !defined(BOOST_CORE_HAS_BUILTIN_BSWAP16) && (defined(BOOST_GCC_VERSION) && BOOST_GCC_VERSION >= 40800)
+#if !defined(BOOST_CORE_HAS_BUILTIN_BSWAP16) && (defined(BOOST_GCC) && BOOST_GCC >= 40800)
 #  define BOOST_CORE_HAS_BUILTIN_BSWAP16
 #endif