diff --git a/services/cache/dns.c b/services/cache/dns.c
index c593dcd72..f6ce272a5 100644
--- a/services/cache/dns.c
+++ b/services/cache/dns.c
@@ -712,10 +712,16 @@ struct dns_msg*
 dns_msg_deepcopy_region(struct dns_msg* origin, struct regional* region)
 {
 	size_t i;
+	struct ub_packed_rrset_key** saved_rrsets;
 	struct dns_msg* res = NULL;
+	size_t rep_alloc_size = sizeof(struct reply_info)
+		- sizeof(struct rrset_ref);  /* this is the size of res->rep
+						allocated in gen_dns_msg() */
 	res = gen_dns_msg(region, &origin->qinfo, origin->rep->rrset_count);
 	if(!res) return NULL;
-	*res->rep = *origin->rep;
+	saved_rrsets = res->rep->rrsets; /* save rrsets alloc by gen_dns_msg */
+	memcpy(res->rep, origin->rep, rep_alloc_size);
+	res->rep->rrsets = saved_rrsets;
 	if(origin->rep->reason_bogus_str) {
 		res->rep->reason_bogus_str = regional_strdup(region,
 			origin->rep->reason_bogus_str);