diff --git a/src/mame/drivers/bfcobra.cpp b/src/mame/drivers/bfcobra.cpp
index 66b3481dad3..a182d6567f6 100644
--- a/src/mame/drivers/bfcobra.cpp
+++ b/src/mame/drivers/bfcobra.cpp
@@ -1655,7 +1655,7 @@ static MACHINE_CONFIG_START( bfcobra )
 
 	MCFG_SPEAKER_STANDARD_MONO("mono")
 
-	MCFG_SOUND_ADD("aysnd", AY8910, M6809_XTAL)
+	MCFG_SOUND_ADD("aysnd", AY8910, M6809_XTAL / 4)
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.20)
 
 	MCFG_SOUND_ADD("upd", UPD7759, UPD7759_STANDARD_CLOCK)