diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 77584422ed08..dbd9c196fcfb 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -5773,6 +5773,17 @@ int mlxsw_sp_netdevice_router_port_event(struct net_device *dev)
 	if (err)
 		goto err_rif_fdb_op;
 
+	if (rif->mtu != dev->mtu) {
+		struct mlxsw_sp_vr *vr;
+
+		/* The RIF is relevant only to its mr_table instance, as unlike
+		 * unicast routing, in multicast routing a RIF cannot be shared
+		 * between several multicast routing tables.
+		 */
+		vr = &mlxsw_sp->router->vrs[rif->vr_id];
+		mlxsw_sp_mr_rif_mtu_update(vr->mr4_table, rif, dev->mtu);
+	}
+
 	ether_addr_copy(rif->addr, dev->dev_addr);
 	rif->mtu = dev->mtu;