diff --git a/Engine.Core/Universe.cs b/Engine.Core/Universe.cs
index bb00b98..49cc883 100644
--- a/Engine.Core/Universe.cs
+++ b/Engine.Core/Universe.cs
@@ -22,7 +22,7 @@ public class Universe : BaseEntity, IUniverse
     private readonly Event<IInitializable>.EventHandler delegateOnUniverseObjectFinalize = null!;
     private readonly Event<IUniverseObject, IUniverseObject.ExitedUniverseArguments>.EventHandler delegateOnUniverseObjectExitedUniverse = null!;
 
-    private readonly List<IUniverseObject> _universeObjects = new(Constants.UNIVERSE_OBJECTS_SIZE_INITIAL);
+    private readonly FastList<IUniverseObject> _universeObjects = new(Constants.UNIVERSE_OBJECTS_SIZE_INITIAL);
     private float _timeScale = 1f;
 
     public Universe()
diff --git a/Engine.Core/UniverseObject.cs b/Engine.Core/UniverseObject.cs
index d70e995..e653f1c 100644
--- a/Engine.Core/UniverseObject.cs
+++ b/Engine.Core/UniverseObject.cs
@@ -19,7 +19,7 @@ public class UniverseObject : BaseEntity, IUniverseObject
     private IUniverse _universe = null!;
     private IBehaviourController _behaviourController = null!;
     private bool _isActive = false;
-    private readonly List<IUniverseObject> _children = [];
+    private readonly FastList<IUniverseObject> _children = [];
     private IUniverseObject? _parent = null;
 
     public IReadOnlyList<IUniverseObject> Children => _children;