diff --git a/src/mess/drivers/c128.c b/src/mess/drivers/c128.c
index c2f0c4aeb40..0c0aaac1716 100644
--- a/src/mess/drivers/c128.c
+++ b/src/mess/drivers/c128.c
@@ -1469,7 +1469,7 @@ static MACHINE_CONFIG_START( ntsc, c128_state )
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
 
 	// devices
-	MCFG_DEVICE_ADD(MOS8722_TAG, MOS8722, 0)
+	MCFG_DEVICE_ADD(MOS8722_TAG, MOS8722, VIC6567_CLOCK*2)
 	MCFG_MOS8722_Z80EN_CALLBACK(WRITELINE(c128_state, mmu_z80en_w))
 	MCFG_MOS8722_FSDIR_CALLBACK(WRITELINE(c128_state, mmu_fsdir_w))
 	MCFG_MOS8722_GAME_CALLBACK(READLINE(c128_state, mmu_game_r))
@@ -1607,7 +1607,7 @@ static MACHINE_CONFIG_START( pal, c128_state )
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
 
 	// devices
-	MCFG_DEVICE_ADD(MOS8722_TAG, MOS8722, 0)
+	MCFG_DEVICE_ADD(MOS8722_TAG, MOS8722, VIC6569_CLOCK)
 	MCFG_MOS8722_Z80EN_CALLBACK(WRITELINE(c128_state, mmu_z80en_w))
 	MCFG_MOS8722_FSDIR_CALLBACK(WRITELINE(c128_state, mmu_fsdir_w))
 	MCFG_MOS8722_GAME_CALLBACK(READLINE(c128_state, mmu_game_r))