diff --git a/src/mame/drivers/prehisle.c b/src/mame/drivers/prehisle.c
index 7bdf9fd74bc..f485ac61bf5 100644
--- a/src/mame/drivers/prehisle.c
+++ b/src/mame/drivers/prehisle.c
@@ -139,7 +139,7 @@ static INPUT_PORTS_START( prehisle )
 	PORT_DIPNAME( 0x40, 0x40, DEF_STR( Allow_Continue ) ) PORT_DIPLOCATION("SW2:7")
 	PORT_DIPSETTING(    0x00, DEF_STR( No ) )
 	PORT_DIPSETTING(    0x40, DEF_STR( Yes ) )
-	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_CUSTOM ) PORT_VBLANK("screen")
+	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_CUSTOM ) PORT_VBLANK("screen")
 INPUT_PORTS_END
 
 /******************************************************************************/