--- a/src/newgrf_sound.h	Sat Dec 29 05:15:13 2007 +0000
+++ b/src/newgrf_sound.h	Sat Dec 29 09:24:26 2007 +0000
@@ -5,6 +5,8 @@
 #ifndef NEWGRF_SOUND_H
 #define NEWGRF_SOUND_H
 
+#include "sound_type.h"
+
 enum VehicleSoundEvent {
 	VSE_START        = 1,
 	VSE_TUNNEL       = 2,