diff --git a/include/wx/defs.h b/include/wx/defs.h
index 81098fc9b8..241b8991f0 100644
--- a/include/wx/defs.h
+++ b/include/wx/defs.h
@@ -302,7 +302,7 @@ typedef short int WXTYPE;
 
 /* wxFALLTHROUGH is used to notate explicit fallthroughs in switch statements */
 
-#if __cplusplus >= 201703L
+#if __cplusplus >= 201703L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
     #define wxFALLTHROUGH [[fallthrough]]
 #elif __cplusplus >= 201103L && defined(__has_warning) && WX_HAS_CLANG_FEATURE(cxx_attributes)
     #define wxFALLTHROUGH [[clang::fallthrough]]