diff --git a/src/api_s2c/heroskin/ApiUplv.ts b/src/api_s2c/heroskin/ApiUplv.ts
index 714a1c3..dc281e2 100644
--- a/src/api_s2c/heroskin/ApiUplv.ts
+++ b/src/api_s2c/heroskin/ApiUplv.ts
@@ -15,7 +15,7 @@ export default async function (call: ApiCall<ReqUplv, ResUplv>) {
 
     let need = [];
     for (let i = 0; i < call.req.lv; i++) {
-        need.concat(
+        need = need.concat(
             G.gc.heroSkinLv[skinconf.colour][cur_lv + i].need
         )
     }