diff --git a/tools/monster/gen-combat-monster.mjs b/tools/monster/gen-combat-monster.mjs
index 4270164..b5afece 100644
--- a/tools/monster/gen-combat-monster.mjs
+++ b/tools/monster/gen-combat-monster.mjs
@@ -63,8 +63,8 @@ function patchMap(nn) {
     if (existing) {
       // 사용자가 메이커에서 설정한 값 보존 — 누락된 키만 기본값 채움
       if (existing.Enable === undefined) existing.Enable = true;
-      if (existing.EnemyId === undefined) existing.EnemyId = NAME_TO_ENEMY[name] || DEFAULT_ENEMY;
-      if (existing.Group === undefined) existing.Group = 'combat';
+      if (existing.EnemyId == null) existing.EnemyId = NAME_TO_ENEMY[name] || DEFAULT_ENEMY;
+      if (existing.Group == null) existing.Group = 'combat';
       kept++;
     } else {
       comps.push({ '@type': 'script.CombatMonster', Enable: true, EnemyId: NAME_TO_ENEMY[name] || DEFAULT_ENEMY, Group: 'combat' });