diff --git a/src/Avalonia.Visuals/Rendering/SceneGraph/VisualNode.cs b/src/Avalonia.Visuals/Rendering/SceneGraph/VisualNode.cs
index c3dfe12b2d..f579bf0a62 100644
--- a/src/Avalonia.Visuals/Rendering/SceneGraph/VisualNode.cs
+++ b/src/Avalonia.Visuals/Rendering/SceneGraph/VisualNode.cs
@@ -184,7 +184,7 @@ namespace Avalonia.Rendering.SceneGraph
                 return;
             }
 
-            var keys = new List<long>();
+            var keys = new List<long>(Visual.VisualChildren.Count);
 
             for (var i = 0; i < Visual.VisualChildren.Count; ++i)
             {