diff --git a/src/mame/drivers/deco_mlc.c b/src/mame/drivers/deco_mlc.c
index e1d5dd6d369..d56109d8882 100644
--- a/src/mame/drivers/deco_mlc.c
+++ b/src/mame/drivers/deco_mlc.c
@@ -278,7 +278,7 @@ static ADDRESS_MAP_START( readmem, ADDRESS_SPACE_PROGRAM, 32 )
 	AM_RANGE(0x0300000, 0x0307fff) AM_READ(SMH_RAM) AM_MIRROR(0xff000000)
 	AM_RANGE(0x0400000, 0x0400003) AM_READ_PORT("INPUTS") AM_MIRROR(0xff000000)
 	AM_RANGE(0x0440000, 0x044001f) AM_READ(test3_r)	AM_MIRROR(0xff000000)
-	AM_RANGE(0x0600004, 0x0600007) AM_DEVREAD8("ymz", ymz280b_r, 0xff000000) AM_MIRROR(0xff000000)
+	AM_RANGE(0x0600000, 0x0600007) AM_DEVREAD8("ymz", ymz280b_r, 0xff000000) AM_MIRROR(0xff000000)
 	AM_RANGE(0x070f000, 0x070ffff) AM_READ(stadhr96_prot_146_r) AM_MIRROR(0xff000000)
 ADDRESS_MAP_END