diff --git a/src/Battling/Models/Creature.hpp b/src/Battling/Models/Creature.hpp
index cd99b92..24e81ff 100644
--- a/src/Battling/Models/Creature.hpp
+++ b/src/Battling/Models/Creature.hpp
@@ -131,7 +131,7 @@ namespace CreatureLib::Battling {
         void ClearBattleData() noexcept;
         inline const ArbUt::OptionalBorrowedPtr<Battle>& GetBattle() const { return _battleData.Battle; }
         inline const ArbUt::OptionalBorrowedPtr<BattleSide>& GetBattleSide() const { return _battleData.Side; }
-        inline void SetOnBattleField(bool value);
+        void SetOnBattleField(bool value);
         inline void SetBattleIndex(const CreatureIndex& index) { _battleData.Index = index; }
         inline const CreatureIndex& GetBattleIndex() const noexcept { return _battleData.Index; }
         inline bool IsOnBattleField() const { return _battleData.OnBattleField; }