diff --git a/src/mame/drivers/bfm_sc4.c b/src/mame/drivers/bfm_sc4.c
index 3909b632db2..074a411a155 100644
--- a/src/mame/drivers/bfm_sc4.c
+++ b/src/mame/drivers/bfm_sc4.c
@@ -2813,7 +2813,7 @@ ROM_START( ad4ctla )
 	ROM_REGION( 0x400000, "maincpu", ROMREGION_ERASE00 )
 	/* not sure which of the regular Cop the Lot roms these go with */
 	
-	ROM_REGION( 0x400000, "maincpu", ROMREGION_ERASEFF )
+	ROM_REGION( 0x400000, "adder4", ROMREGION_ERASEFF )
 	ROM_LOAD16_BYTE( "95780024.lo", 0x00001, 0x100000, CRC(654e4428) SHA1(92f6074461bb58120401b0e1981e48d13cd467dd) )
 	ROM_LOAD16_BYTE( "95780025.hi", 0x00000, 0x100000, CRC(7397e2e4) SHA1(d22cc364aeb096ca03cd4642a22bd37fe548e2a1) )
 	sc_ctlcl_others