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
@@ -419,6 +419,40 @@
 VNET_DEFINE(uint32_t, pf_hashseed);
 #define	V_pf_hashseed	VNET(pf_hashseed)
 
+#ifdef __LP64__
+static int
+pf_bcmp_state_key(struct pf_state_key *k1_orig, struct pf_state_key_cmp *k2_orig)
+{
+	unsigned long *k1 = (unsigned long *)k1_orig;
+	unsigned long *k2 = (unsigned long *)k2_orig;
+
+	if (k1[0] != k2[0])
+		return (1);
+
+	if (k1[1] != k2[1])
+		return (1);
+
+	if (k1[2] != k2[2])
+		return (1);
+
+	if (k1[3] != k2[3])
+		return (1);
+
+	if (k1[4] != k2[4])
+		return (1);
+
+	return (0);
+}
+_Static_assert(sizeof(struct pf_state_key_cmp) == 40, "bad size of pf_state_key_cmp");
+#else
+static inline int
+pf_bcmp_state_key(struct pf_state_key *k1_orig, struct pf_state_key_cmp *k2_orig)
+{
+
+	return (bcmp(k1_orig, k2_orig, sizeof(struct pf_state_key_cmp)));
+}
+#endif
+
 int
 pf_addr_cmp(struct pf_addr *a, struct pf_addr *b, sa_family_t af)
 {
@@ -1174,7 +1208,7 @@
 
 keyattach:
 	LIST_FOREACH(cur, &kh->keys, entry)
-		if (bcmp(cur, sk, sizeof(struct pf_state_key_cmp)) == 0)
+		if (pf_bcmp_state_key(cur, (struct pf_state_key_cmp *)sk) == 0)
 			break;
 
 	if (cur != NULL) {
@@ -1480,7 +1514,7 @@
 
 	PF_HASHROW_LOCK(kh);
 	LIST_FOREACH(sk, &kh->keys, entry)
-		if (bcmp(sk, key, sizeof(struct pf_state_key_cmp)) == 0)
+		if (pf_bcmp_state_key(sk, key) == 0)
 			break;
 	if (sk == NULL) {
 		PF_HASHROW_UNLOCK(kh);
@@ -1527,7 +1561,7 @@
 
 	PF_HASHROW_LOCK(kh);
 	LIST_FOREACH(sk, &kh->keys, entry)
-		if (bcmp(sk, key, sizeof(struct pf_state_key_cmp)) == 0)
+		if (pf_bcmp_state_key(sk, key) == 0)
 			break;
 	if (sk == NULL) {
 		PF_HASHROW_UNLOCK(kh);