--- a/sys/netgraph7/ng_fec.c
+++ b/sys/netgraph7/ng_fec.c
@@ -511,6 +511,9 @@
 	IFP2NG(bifp) = NULL;
 	IF_AFDATA_UNLOCK(bifp);
 
+	/* Release the multicast memberships we programmed for this port. */
+	ng_fec_ether_cmdmulti(priv->ifp, p, 0);
+
 	/* Delete port */
 	TAILQ_REMOVE(&b->ng_fec_ports, p, fec_list);
 	kfree(p, M_NETGRAPH);