diff --git a/sys/netinet6/in6_var.h b/sys/netinet6/in6_var.h
index 260e9443a300..a472a24ef955 100644
--- a/sys/netinet6/in6_var.h
+++ b/sys/netinet6/in6_var.h
@@ -503,6 +503,7 @@ MALLOC_DECLARE(M_IP6MADDR);
 /* struct in6_ifaddr *ia; */				\
 do {									\
 	struct ifaddr *ifa;						\
+	IF_ADDR_LOCK_ASSERT(ifp);					\
 	TAILQ_FOREACH(ifa, &(ifp)->if_addrhead, ifa_link) {		\
 		if (ifa->ifa_addr->sa_family == AF_INET6)		\
 			break;						\
diff --git a/sys/netinet6/mld6.c b/sys/netinet6/mld6.c
index 29b71be258dd..0d05522b729c 100644
--- a/sys/netinet6/mld6.c
+++ b/sys/netinet6/mld6.c
@@ -360,9 +360,12 @@ mld6_input(struct mbuf *m, int off)
 		 */
 		timer = ntohs(mldh->mld_maxdelay);
 
+		IF_ADDR_LOCK(ifp);
 		IFP_TO_IA6(ifp, ia);
-		if (ia == NULL)
+		if (ia == NULL) {
+			IF_ADDR_UNLOCK(ifp);
 			break;
+		}
 
 		/*
 		 * XXX: System timer resolution is too low to handle Max
@@ -374,7 +377,6 @@ mld6_input(struct mbuf *m, int off)
 		if (timer == 0 && mldh->mld_maxdelay)
 			timer = 1;
 
-		IF_ADDR_LOCK(ifp);
 		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
 			if (ifma->ifma_addr->sa_family != AF_INET6)
 				continue;