diff --git a/src/mame/misc/4enraya.cpp b/src/mame/misc/4enraya.cpp
index 7db07c243ca..1234011ba04 100644
--- a/src/mame/misc/4enraya.cpp
+++ b/src/mame/misc/4enraya.cpp
@@ -432,9 +432,7 @@ static INPUT_PORTS_START( 4enraya )
 	PORT_DIPNAME( 0x01, 0x01, "Speed" )                 PORT_DIPLOCATION("SW1:1")
 	PORT_DIPSETTING(    0x01, "Slow" )
 	PORT_DIPSETTING(    0x00, "Fast" )
-	PORT_DIPNAME( 0x02, 0x00, DEF_STR( Demo_Sounds ) )  PORT_DIPLOCATION("SW1:2")
-	PORT_DIPSETTING(    0x02, DEF_STR( Off ) )
-	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
+	PORT_DIPUNKNOWN_DIPLOC( 0x02, 0x02, "SW1:2" ) //It was identified with "Demo Sound", but not worked
 	PORT_DIPNAME( 0x04, 0x04, "Pieces" )                PORT_DIPLOCATION("SW1:3")
 	PORT_DIPSETTING(    0x04, "30" )
 	PORT_DIPSETTING(    0x00, "16" )