diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index ade108232048..e1f3d04a8c90 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -258,6 +258,9 @@ int stmmac_mdio_unregister(struct net_device *ndev)
 {
 	struct stmmac_priv *priv = netdev_priv(ndev);
 
+	if (!priv->mii)
+		return 0;
+
 	mdiobus_unregister(priv->mii);
 	priv->mii->priv = NULL;
 	mdiobus_free(priv->mii);