diff --git a/include/boost/detail/utf8_codecvt_facet.hpp b/include/boost/detail/utf8_codecvt_facet.hpp
index 65c5e4e..c57cd02 100644
--- a/include/boost/detail/utf8_codecvt_facet.hpp
+++ b/include/boost/detail/utf8_codecvt_facet.hpp
@@ -92,8 +92,7 @@ namespace std {
 }
 #endif
 
-#if !defined(__MSL_CPP__) && !defined(__LIBCOMO__) \
-    && !defined(_LIBCPP_VERSION)
+#if defined(_MSC_VER) && (_MSC_VER < 1700)
     #define BOOST_CODECVT_DO_LENGTH_CONST const
 #else
     #define BOOST_CODECVT_DO_LENGTH_CONST