diff --git a/toml/version.hpp b/toml/version.hpp
index 1678010..2d356a0 100644
--- a/toml/version.hpp
+++ b/toml/version.hpp
@@ -29,7 +29,7 @@
 #  define TOML11_CPLUSPLUS_STANDARD_VERSION 201703L
 #elif defined(TOML11_ENFORCE_CXX20)
 #  define TOML11_CPLUSPLUS_STANDARD_VERSION 202002L
-#elif defined(_MSVC_LANG)
+#elif defined(_MSVC_LANG) && defined(_MSC_VER) && 1910 <= _MSC_VER
 #  define TOML11_CPLUSPLUS_STANDARD_VERSION _MSVC_LANG
 #else
 #  define TOML11_CPLUSPLUS_STANDARD_VERSION __cplusplus