diff --git a/currency.h b/currency.h
index bd13d95fdf..7c368267d5 100644
--- a/currency.h
+++ b/currency.h
@@ -1,3 +1,5 @@
+/* $Id$ */
+
 #ifndef CURRENCY_H
 #define CURRENCY_H
 
diff --git a/main_gui.c b/main_gui.c
index 4a16b4621d..50252f3670 100644
--- a/main_gui.c
+++ b/main_gui.c
@@ -2,6 +2,7 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "currency.h"
 #include "functions.h"
 #include "spritecache.h"
 #include "strings.h"