diff --git a/sys/net/application_layer/dhcpv6/client.c b/sys/net/application_layer/dhcpv6/client.c
index cc2d2f7f63..237a86a44a 100644
--- a/sys/net/application_layer/dhcpv6/client.c
+++ b/sys/net/application_layer/dhcpv6/client.c
@@ -1016,6 +1016,10 @@ static bool _parse_reply(uint8_t *rep, size_t len, uint8_t request_type)
             default:
                 break;
         }
+        /* 0 option is used as an end marker, len can include bogus bytes */
+        if (!byteorder_ntohs(opt->type)) {
+            break;
+        }
     }
     if ((cid == NULL) || (sid == NULL)) {
         DEBUG("DHCPv6 client: ADVERTISE does not contain either server ID "