diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index 8d9cc2157afd103c4d0282c8b74973d6c8f6256e..7423262ce5907f9d05ac6e44025c144c86e89618 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -122,7 +122,7 @@ static int adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
 		 * programmed with (2^32 – <new_sec_value>)
 		 */
 		if (gmac4)
-			sec = (100000000ULL - sec);
+			sec = -sec;
 
 		value = readl(ioaddr + PTP_TCR);
 		if (value & PTP_TCR_TSCTRLSSR)