diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index b2a707e2ef43..d64116e0543e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -365,6 +365,9 @@ int stmmac_mdio_register(struct net_device *ndev)
 
 	new_bus->name = "stmmac";
 
+	if (priv->plat->has_gmac4)
+		new_bus->probe_capabilities = MDIOBUS_C22_C45;
+
 	if (priv->plat->has_xgmac) {
 		new_bus->read = &stmmac_xgmac2_mdio_read;
 		new_bus->write = &stmmac_xgmac2_mdio_write;