--- a/src/newgrf_spritegroup.h	Fri Aug 03 19:16:36 2007 +0000
+++ b/src/newgrf_spritegroup.h	Fri Aug 03 22:09:42 2007 +0000
@@ -188,7 +188,7 @@
 
 
 struct ResolverObject {
-	uint16 callback;
+	CallbackID callback;
 	uint32 callback_param1;
 	uint32 callback_param2;