diff --git a/sys/netpfil/pf/if_pfsync.c b/sys/netpfil/pf/if_pfsync.c
--- a/sys/netpfil/pf/if_pfsync.c
+++ b/sys/netpfil/pf/if_pfsync.c
@@ -662,6 +662,11 @@
 
 cleanup_state:	/* pf_state_insert() frees the state keys. */
 	if (st) {
+		/*
+		 * The state has not yet been inserted or the insertion has
+		 * failed.
+		 */
+		st->timeout = PFTM_UNLINKED;
 		pf_free_state(st);
 	}
 	return (error);