diff --git a/SDK/include/NDK/World.hpp b/SDK/include/NDK/World.hpp
index ded8c4ff5..5e819e517 100644
--- a/SDK/include/NDK/World.hpp
+++ b/SDK/include/NDK/World.hpp
@@ -86,7 +86,7 @@ namespace Ndk
 				EntityBlock(EntityBlock&& block) = default;
 
 				Entity entity;
-				unsigned int aliveIndex;
+				std::size_t aliveIndex;
 			};
 
 			std::vector<std::unique_ptr<BaseSystem>> m_systems;