diff --git a/subsys/net/ip/l2/ethernet.c b/subsys/net/ip/l2/ethernet.c
index d915cd94b40..a19a288d120 100644
--- a/subsys/net/ip/l2/ethernet.c
+++ b/subsys/net/ip/l2/ethernet.c
@@ -75,7 +75,8 @@ static inline void ethernet_update_length(struct net_if *iface,
 		       NET_IPV4_BUF(buf)->len[1]);
 	} else {
 		len = ((NET_IPV6_BUF(buf)->len[0] << 8) +
-		       NET_IPV6_BUF(buf)->len[1]);
+		       NET_IPV6_BUF(buf)->len[1]) +
+			NET_IPV6H_LEN;
 	}
 
 	if (len < NET_ETH_MINIMAL_FRAME_SIZE - sizeof(struct net_eth_hdr)) {