diff --git a/drivers/net/ethernet/freescale/fec_mpc52xx_phy.c b/drivers/net/ethernet/freescale/fec_mpc52xx_phy.c
index 2c37004bb0fe9..3d073f0fae630 100644
--- a/drivers/net/ethernet/freescale/fec_mpc52xx_phy.c
+++ b/drivers/net/ethernet/freescale/fec_mpc52xx_phy.c
@@ -94,7 +94,7 @@ static int mpc52xx_fec_mdio_probe(struct platform_device *of)
 		goto out_free;
 	}
 
-	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res.start);
 	bus->priv = priv;
 
 	bus->parent = dev;
diff --git a/drivers/net/ethernet/freescale/fs_enet/mii-bitbang.c b/drivers/net/ethernet/freescale/fs_enet/mii-bitbang.c
index e6b2d7452fe76..66038e2a4ae3a 100644
--- a/drivers/net/ethernet/freescale/fs_enet/mii-bitbang.c
+++ b/drivers/net/ethernet/freescale/fs_enet/mii-bitbang.c
@@ -123,7 +123,7 @@ static int fs_mii_bitbang_init(struct mii_bus *bus, struct device_node *np)
 	 * we get is an int, and the odds of multiple bitbang mdio buses
 	 * is low enough that it's not worth going too crazy.
 	 */
-	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res.start);
 
 	data = of_get_property(np, "fsl,mdio-pin", &len);
 	if (!data || len != 4)