diff --git a/src/shared/public/heroskin.ts b/src/shared/public/heroskin.ts
index b0cb955..bb878e8 100644
--- a/src/shared/public/heroskin.ts
+++ b/src/shared/public/heroskin.ts
@@ -12,7 +12,7 @@ export default class HeroSkinShared {
         let buff = {};
         let skin = G.gc.heroSkin[skid];
         for (let i = 1; i <= lv; i++) {
-            for (let k in G.gc.heroSkinLv[skin.colour][i].buff) {
+            for (let k in (G.gc.heroSkinLv[skin.colour][i]?.buff || {})) {
                 buff[k] = (buff[k] || 0) + G.gc.heroSkinLv[skin.colour][i].buff[k];
             }
         }