diff --git a/server/protocol.def b/server/protocol.def
index 20b87db5d5b..6b510497f8c 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -24,9 +24,12 @@
 
 @HEADER  /* start of C declarations */
 
+#include <stdarg.h>
 #include <stdlib.h>
 #include <time.h>
-#include "winbase.h"
+
+#include <windef.h>
+#include <winbase.h>
 
 struct request_header
 {