diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
index b7ad3565566cc..c5ee79d8a8c56 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
@@ -206,6 +206,7 @@ void stmmac_ptp_unregister(struct stmmac_priv *priv)
 {
 	if (priv->ptp_clock) {
 		ptp_clock_unregister(priv->ptp_clock);
+		priv->ptp_clock = NULL;
 		pr_debug("Removed PTP HW clock successfully on %s\n",
 			 priv->dev->name);
 	}