diff --git a/src/core/dns.c b/src/core/dns.c
index 93657f94..45b416b4 100644
--- a/src/core/dns.c
+++ b/src/core/dns.c
@@ -1083,7 +1083,7 @@ dns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t
             /* deallocate memory and return */
             goto memerr;
           } else {
-            res_idx = SIZEOF_DNS_ANSWER + htons(ans.len);
+            res_idx += SIZEOF_DNS_ANSWER + htons(ans.len);
           }
           --nanswers;
         }