diff --git a/sys/net/pf/pf.c b/sys/net/pf/pf.c
--- a/sys/net/pf/pf.c
+++ b/sys/net/pf/pf.c
@@ -5731,7 +5731,7 @@
 
 				if (PF_ANEQ(pd2.dst,
 				    &nk->addr[pd2.didx], pd2.af))
-					pf_change_icmp(pd2.src, NULL,
+					pf_change_icmp(pd2.dst, NULL,
 					    NULL, /* XXX Inbound NAT? */
 					    &nk->addr[pd2.didx], 0, NULL,
 					    pd2.ip_sum, icmpsum,