diff --git a/dummy_land.c b/dummy_land.c
--- a/dummy_land.c
+++ b/dummy_land.c
@@ -1,6 +1,7 @@
 #include "stdafx.h"
 #include "openttd.h"
 #include "table/strings.h"
+#include "functions.h"
 #include "viewport.h"
 #include "command.h"