diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/Extensions/NodeExtensions.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/Extensions/NodeExtensions.cs
index e9d8b98344..df0e839866 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/Extensions/NodeExtensions.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/Extensions/NodeExtensions.cs
@@ -129,7 +129,8 @@ namespace Godot
         /// </returns>
         public T GetChildOrNull<T>(int idx, bool includeInternal = false) where T : class
         {
-            return GetChild(idx, includeInternal) as T;
+            int count = GetChildCount(includeInternal);
+            return idx >= -count && idx < count ? GetChild(idx, includeInternal) as T : null;
         }
 
         /// <summary>