diff --git a/Engine.Core/Abstract/IBehaviourController.cs b/Engine.Core/Abstract/IBehaviourController.cs
index 64fa28e..17e7e57 100644
--- a/Engine.Core/Abstract/IBehaviourController.cs
+++ b/Engine.Core/Abstract/IBehaviourController.cs
@@ -60,7 +60,7 @@ public interface IBehaviourController : IInitializable, IHasHierarchyObject, IEn
     /// </summary>
     /// <typeparam name="T">The type of <see cref="IBehaviour"/>s to get.</typeparam>
     /// <returns>A list of <see cref="IBehaviour"/>s of the specified type.</returns>
-    IList<T> GetBehaviours<T>();
+    IReadOnlyList<T> GetBehaviours<T>();
 
     /// <summary>
     /// Gets all <see cref="IBehaviour"/>s of the specified type and stores them in the provided list.
diff --git a/Engine.Core/BehaviourController.cs b/Engine.Core/BehaviourController.cs
index 3a9615e..0d80b1d 100644
--- a/Engine.Core/BehaviourController.cs
+++ b/Engine.Core/BehaviourController.cs
@@ -72,7 +72,7 @@ public class BehaviourController : IBehaviourController
         return default;
     }
 
-    public IList<T> GetBehaviours<T>()
+    public IReadOnlyList<T> GetBehaviours<T>()
     {
         List<T>? behaviours = null;
         foreach (IBehaviour behaviourItem in this.behaviours)