diff --git a/drivers/net/ethernet/broadcom/sb1250-mac.c b/drivers/net/ethernet/broadcom/sb1250-mac.c
index 8fa7abc53ec69a38fce149dbf37acb5eca2a2cf1..084904ceaa301b4fd76f00a8411433ec1711b49e 100644
--- a/drivers/net/ethernet/broadcom/sb1250-mac.c
+++ b/drivers/net/ethernet/broadcom/sb1250-mac.c
@@ -2259,7 +2259,8 @@ static int sbmac_init(struct platform_device *pldev, long long base)
 	}
 
 	sc->mii_bus->name = sbmac_mdio_string;
-	snprintf(sc->mii_bus->id, MII_BUS_ID_SIZE, "%x", idx);
+	snprintf(sc->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
+		pldev->name, idx);
 	sc->mii_bus->priv = sc;
 	sc->mii_bus->read = sbmac_mii_read;
 	sc->mii_bus->write = sbmac_mii_write;