diff --git a/os2.c b/os2.c
--- a/os2.c
+++ b/os2.c
@@ -1,5 +1,5 @@
 #include "stdafx.h"
-#include "ttd.h"
+#include "openttd.h"
 #include "window.h"
 #include "string.h"
 #include "table/strings.h"