diff --git a/src/rooms/logic/Handler/BattleHandler.ts b/src/rooms/logic/Handler/BattleHandler.ts
index a29b92f..d458c7e 100644
--- a/src/rooms/logic/Handler/BattleHandler.ts
+++ b/src/rooms/logic/Handler/BattleHandler.ts
@@ -940,7 +940,7 @@ export class BattleHandler {
             let natkbk = __indexOfAttackBk(nstart, atkobj);
             if(natkbk){
                 let atkbkobj = skillres[natkbk];
-                atkbkobj.res.forEach((item: SkillResult) => {
+                atkbkobj.res && atkbkobj.res.forEach((item: SkillResult) => {
                     if(item.bsuccess){
                         if(item.effect_type == SkillEffectType.CHG_AP || item.effect_type == SkillEffectType.CHG_HP){
                             atkobj.success(item.effect_type, item.effect_res, true);