diff --git a/source/vba/System.h b/source/vba/System.h
index 8f31838..c31e968 100644
--- a/source/vba/System.h
+++ b/source/vba/System.h
@@ -51,17 +51,12 @@ extern u32 systemReadJoypad(int);
 extern u32 systemGetClock();
 extern void systemMessage(int, const char *, ...);
 extern void systemSetTitle(const char *);
-extern SoundDriver * systemSoundInit();
-extern void systemOnWriteDataToSoundBuffer(const u16 * finalWave, int length);
-extern void systemOnSoundShutdown();
-// old defs
 extern void systemWriteDataToSoundBuffer();
 extern void systemSoundShutdown();
 extern void systemSoundPause();
 extern void systemSoundResume();
 extern void systemSoundReset();
 extern bool systemSoundInit();
-// end old defs
 extern void systemScreenMessage(const char *);
 extern void systemUpdateMotionSensor();
 extern int  systemGetSensorX();