diff --git a/src/mame/drivers/tmnt.cpp b/src/mame/drivers/tmnt.cpp
index c1895ba01c0..3643840ad41 100644
--- a/src/mame/drivers/tmnt.cpp
+++ b/src/mame/drivers/tmnt.cpp
@@ -2087,7 +2087,7 @@ static MACHINE_CONFIG_START( tmnt, tmnt_state )
 	MCFG_SCREEN_REFRESH_RATE(60)
 	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500) /* not accurate */)
 	MCFG_SCREEN_SIZE(64*8, 32*8)
-	MCFG_SCREEN_VISIBLE_AREA(12*8+8, (64-12)*8-1, 2*8, 30*8-1 )
+	MCFG_SCREEN_VISIBLE_AREA(12*8, (64-12)*8-1, 2*8, 30*8-1 )
 	// verified against real hardware
 	MCFG_SCREEN_UPDATE_DRIVER(tmnt_state, screen_update_tmnt)
 	MCFG_SCREEN_PALETTE("palette")
diff --git a/src/mame/drivers/vigilant.cpp b/src/mame/drivers/vigilant.cpp
index 2b538256a0b..944c5cd1239 100644
--- a/src/mame/drivers/vigilant.cpp
+++ b/src/mame/drivers/vigilant.cpp
@@ -485,7 +485,7 @@ static MACHINE_CONFIG_START( vigilant, vigilant_state )
 	MCFG_SCREEN_REFRESH_RATE(55)
 	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500) /* not accurate */)
 	MCFG_SCREEN_SIZE(64*8, 32*8)
-	MCFG_SCREEN_VISIBLE_AREA(16*8, (64-16)*8-1, 0*8, 32*8-1 )
+	MCFG_SCREEN_VISIBLE_AREA((16*8)-1, (64-16)*8-4, 0*8, 32*8-1 )
 	MCFG_SCREEN_UPDATE_DRIVER(vigilant_state, screen_update_vigilant)
 	MCFG_SCREEN_PALETTE("palette")