diff --git a/drivers/ethernet/phy/phy_mii.c b/drivers/ethernet/phy/phy_mii.c
index 2f7654a4f14..a623685b8b5 100644
--- a/drivers/ethernet/phy/phy_mii.c
+++ b/drivers/ethernet/phy/phy_mii.c
@@ -41,7 +41,7 @@ struct phy_mii_dev_data {
 	struct k_work_delayable autoneg_work;
 	bool gigabit_supported;
 	bool restart_autoneg;
-	uint32_t autoneg_timeout;
+	k_timepoint_t autoneg_timeout;
 #endif
 };
 
@@ -213,7 +213,7 @@ static int update_link_state(const struct device *dev)
 	data->restart_autoneg = false;
 
 	/* We have to wait for the auto-negotiation process to complete */
-	data->autoneg_timeout = CONFIG_PHY_AUTONEG_TIMEOUT_MS / MII_AUTONEG_POLL_INTERVAL_MS;
+	data->autoneg_timeout = sys_timepoint_calc(K_MSEC(CONFIG_PHY_AUTONEG_TIMEOUT_MS));
 	return -EINPROGRESS;
 }
 
@@ -245,7 +245,7 @@ static int check_autonegotiation_completion(const struct device *dev)
 	}
 
 	if (!(bmsr_reg & MII_BMSR_AUTONEG_COMPLETE)) {
-		if (data->autoneg_timeout-- == 0U) {
+		if (sys_timepoint_expired(data->autoneg_timeout)) {
 			LOG_DBG("PHY (%d) auto-negotiate timedout", cfg->phy_addr);
 			return -ETIMEDOUT;
 		}