diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
index f8acce5..bc20852 100644
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -2065,7 +2065,7 @@ pf_change_ap(struct mbuf *m, struct pf_addr *a, u_int16_t *p, u_int16_t *ic,
 		    ao.addr16[1], an->addr16[1], 0);
 		*p = pn;
 
-		*pc = pf_cksum_fixup(pf_cksum_fixup(*pc,
+		*pc = pf_proto_cksum_fixup(m, pf_proto_cksum_fixup(m, *pc,
 		    ao.addr16[0], an->addr16[0], u),
 		    ao.addr16[1], an->addr16[1], u);
 
@@ -2074,9 +2074,10 @@ pf_change_ap(struct mbuf *m, struct pf_addr *a, u_int16_t *p, u_int16_t *ic,
 #endif /* INET */
 #ifdef INET6
 	case AF_INET6:
-		*pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
-		    pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
-		    pf_cksum_fixup(pf_cksum_fixup(*pc,
+		*pc = pf_proto_cksum_fixup(m, pf_proto_cksum_fixup(m,
+            pf_proto_cksum_fixup(m, pf_proto_cksum_fixup(m, 
+            pf_proto_cksum_fixup(m, pf_proto_cksum_fixup(m,
+		    pf_proto_cksum_fixup(m, pf_proto_cksum_fixup(m, *pc,
 		    ao.addr16[0], an->addr16[0], u),
 		    ao.addr16[1], an->addr16[1], u),
 		    ao.addr16[2], an->addr16[2], u),