diff --git a/main.c b/main.c
index 8e13648..ea7c53d 100644
--- a/main.c
+++ b/main.c
@@ -23,6 +23,7 @@
 #include "winuser.h"
 #include "winreg.h"
 #include "objbase.h"
+#include "unknwn.h"
 
 #ifdef DEBUG
 #include "wine/debug.h"