diff --git a/NatTypeTester/MainWindow.xaml.cs b/NatTypeTester/MainWindow.xaml.cs
index 0f7e3855c..13768799f 100644
--- a/NatTypeTester/MainWindow.xaml.cs
+++ b/NatTypeTester/MainWindow.xaml.cs
@@ -4,7 +4,6 @@
 using ReactiveMarbles.ObservableEvents;
 using ReactiveUI;
 using System.Reactive.Disposables;
-using System.Reactive.Linq;
 using Volo.Abp.DependencyInjection;
 
 namespace NatTypeTester;