diff --git a/sword2/driver/d_sound.h b/sword2/driver/d_sound.h
index 2ba6cc8fd25..83f3b9db06d 100644
--- a/sword2/driver/d_sound.h
+++ b/sword2/driver/d_sound.h
@@ -38,7 +38,7 @@
 #ifndef D_SOUND_H
 #define D_SOUND_H
 
-#include "sound/mixer.h"
+class SoundMixer;
 
 class Sword2Sound {
 	public: