diff --git a/engine/cdll_int.h b/engine/cdll_int.h
index d45bb9d5..20af4b55 100644
--- a/engine/cdll_int.h
+++ b/engine/cdll_int.h
@@ -93,7 +93,7 @@ typedef struct client_textmessage_s
 	const char	*pMessage;
 } client_textmessage_t;
 
-#if __MSC_VER == 1200
+#if _MSC_VER == 1200
 #define ulonglong_t __int64
 #else
 #define ulonglong_t unsigned long long