diff --git a/include/winnt.h b/include/winnt.h
index 96ed387213b..9d6e05d927c 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -1470,9 +1470,9 @@ typedef CONTEXT *PCONTEXT;
 #define LOCALE_USER_DEFAULT	(MAKELCID(LANG_USER_DEFAULT, SORT_DEFAULT))
 #define LOCALE_NEUTRAL		(MAKELCID(MAKELANGID(LANG_NEUTRAL,SUBLANG_NEUTRAL),SORT_DEFAULT))
 
-#define UNREFERENCED_PARAMETER(u)	(u)
-#define DBG_UNREFERENCED_PARAMETER(u)	(u)
-#define DBG_UNREFERENCED_LOCAL_VARIABLE(u) (u)
+#define UNREFERENCED_PARAMETER(u)	(void)(u)
+#define DBG_UNREFERENCED_PARAMETER(u)	(void)(u)
+#define DBG_UNREFERENCED_LOCAL_VARIABLE(u) (void)(u)
 
 #define LANG_NEUTRAL        0x00
 #define LANG_INVARIANT      0x7f