diff --git a/include/boost/preprocessor/config/config.hpp b/include/boost/preprocessor/config/config.hpp
index 89b7da7..74c8a7d 100644
--- a/include/boost/preprocessor/config/config.hpp
+++ b/include/boost/preprocessor/config/config.hpp
@@ -78,6 +78,7 @@
 #    /* VC++ (C/C++) */
 #    elif defined _MSC_VER && _MSC_VER >= 1400 && (!defined __EDG__ || defined(__INTELLISENSE__)) && !defined __clang__
 #        define BOOST_PP_VARIADICS 1
+#        undef BOOST_PP_VARIADICS_MSVC
 #        define BOOST_PP_VARIADICS_MSVC 1
 #    /* Wave (C/C++), GCC (C++) */
 #    elif defined __WAVE__ && __WAVE_HAS_VARIADICS__ || defined __GNUC__ && defined __GXX_EXPERIMENTAL_CXX0X__ && __GXX_EXPERIMENTAL_CXX0X__
@@ -92,6 +93,7 @@
 #    undef BOOST_PP_VARIADICS
 #    define BOOST_PP_VARIADICS 1
 #    if defined _MSC_VER && _MSC_VER >= 1400 && (defined(__INTELLISENSE__) || !(defined __EDG__ || defined __GCCXML__ || defined __CUDACC__ || defined __PATHSCALE__ || defined __clang__ || defined __DMC__ || defined __CODEGEARC__ || defined __BORLANDC__ || defined __MWERKS__ || defined __SUNPRO_CC || defined __HP_aCC || defined __MRC__ || defined __SC__ || defined __IBMCPP__ || defined __PGI))
+#        undef BOOST_PP_VARIADICS_MSVC
 #        define BOOST_PP_VARIADICS_MSVC 1
 #    endif
 # else