diff --git a/libs/util/sys.c b/libs/util/sys.c
index 7cfdd8134..b0bea97ad 100644
--- a/libs/util/sys.c
+++ b/libs/util/sys.c
@@ -409,7 +409,7 @@ Sys_Quit (void)
 #elif defined (HAVE__VA_COPY)
 # define VA_COPY(a,b) __va_copy (a, b)
 #else
-# define VA_COPY memcpy (a, b, sizeof (a))
+# define VA_COPY(a,b) memcpy (a, b, sizeof (a))
 #endif
 
 void