diff --git a/server/snapshot.c b/server/snapshot.c
index 0ef53708a9b..ccbbe726610 100644
--- a/server/snapshot.c
+++ b/server/snapshot.c
@@ -26,6 +26,7 @@
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdarg.h>
 
 #include "ntstatus.h"
 #define WIN32_NO_STATUS