diff --git a/src/Avalonia.Controls/Grid.cs b/src/Avalonia.Controls/Grid.cs
index c46d221dff..4285ba98ec 100644
--- a/src/Avalonia.Controls/Grid.cs
+++ b/src/Avalonia.Controls/Grid.cs
@@ -7,7 +7,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
-
+using System.Threading;
 using Avalonia;
 using Avalonia.Collections;
 using Avalonia.Media;