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
@@ -3860,7 +3860,7 @@
 	struct pf_keth_ruleset *ruleset = NULL;
 	struct pf_mtag *mtag;
 	struct pf_keth_ruleq *rules;
-	struct pf_addr *src, *dst;
+	struct pf_addr *src = NULL, *dst = NULL;
 	sa_family_t af = 0;
 	uint16_t proto;
 	int asd = 0, match = 0;
@@ -3958,13 +3958,13 @@
 			    "dst");
 			r = TAILQ_NEXT(r, entries);
 		}
-		else if (af != 0 && PF_MISMATCHAW(&r->ipsrc.addr, src, af,
+		else if (src != NULL && PF_MISMATCHAW(&r->ipsrc.addr, src, af,
 		    r->ipsrc.neg, kif, M_GETFIB(m))) {
 			SDT_PROBE3(pf, eth, test_rule, mismatch, r->nr, r,
 			    "ip_src");
 			r = TAILQ_NEXT(r, entries);
 		}
-		else if (af != 0 && PF_MISMATCHAW(&r->ipdst.addr, dst, af,
+		else if (dst != NULL && PF_MISMATCHAW(&r->ipdst.addr, dst, af,
 		    r->ipdst.neg, kif, M_GETFIB(m))) {
 			SDT_PROBE3(pf, eth, test_rule, mismatch, r->nr, r,
 			    "ip_dst");