diff --git a/src/Battling/Models/ExecutingAttack.hpp b/src/Battling/Models/ExecutingAttack.hpp
index f00b709..c65e795 100644
--- a/src/Battling/Models/ExecutingAttack.hpp
+++ b/src/Battling/Models/ExecutingAttack.hpp
@@ -69,7 +69,7 @@ namespace CreatureLib::Battling {
             throw CreatureException("Invalid target requested.");
         }
 
-        bool IsCreatureTarget(Creature* creature) noexcept { return _targets.IndexOf(creature) != -1; }
+        bool IsCreatureTarget(Creature* creature) noexcept { return _targets.IndexOf(creature) != (size_t)-1; }
         const List<Creature*>& GetTargets() noexcept { return _targets; }
         uint8_t GetNumberOfHits() const noexcept { return _numberHits; }