diff --git a/src/apps/mdns/mdns.c b/src/apps/mdns/mdns.c
index efb3b0f6..920424b6 100644
--- a/src/apps/mdns/mdns.c
+++ b/src/apps/mdns/mdns.c
@@ -524,9 +524,8 @@ mdns_build_reverse_v6_domain(struct mdns_domain *domain, const ip6_addr_t *addr)
 {
   int i;
   err_t res;
-
-  LWIP_UNUSED_ARG(res);
   const u8_t *ptr;
+  LWIP_UNUSED_ARG(res);
   if (!domain || !addr) {
     return ERR_ARG;
   }