diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -1353,6 +1353,7 @@
 						    sk : NULL);
 						printf("\n");
 					}
+					s->timeout = PFTM_UNLINKED;
 					PF_HASHROW_UNLOCK(ih);
 					KEYS_UNLOCK();
 					uma_zfree(V_pf_state_key_z, sk);
@@ -1421,6 +1422,7 @@
 	struct pf_keyhash *kh;
 
 	NET_EPOCH_ASSERT();
+	MPASS(s->timeout >= PFTM_MAX);
 
 	pf_sctp_multihome_detach_addr(s);
 
@@ -1552,6 +1554,7 @@
 			break;
 
 	if (cur != NULL) {
+		s->timeout = PFTM_UNLINKED;
 		PF_HASHROW_UNLOCK(ih);
 		if (V_pf_status.debug >= PF_DEBUG_MISC) {
 			printf("pf: state ID collision: "