diff --git a/polymer/eduke32/build/include/compat.h b/polymer/eduke32/build/include/compat.h
index 99463048b..8c474548a 100644
--- a/polymer/eduke32/build/include/compat.h
+++ b/polymer/eduke32/build/include/compat.h
@@ -26,11 +26,13 @@
 # define __has_extension __has_feature // Compatibility with pre-3.0 compilers.
 #endif
 
+#if defined(_MSC_VER) && _MSC_FULL_VER < 180031101
 #ifdef UNREFERENCED_PARAMETER
 #undef UNREFERENCED_PARAMETER
 #endif
 
 #define UNREFERENCED_PARAMETER(x) x = x
+#endif
 
 #if defined __GNUC__ || defined __clang__
 # define ATTRIBUTE(attrlist) __attribute__(attrlist)