diff --git a/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml b/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml
index d47deb2e..2baea96c 100644
--- a/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml
+++ b/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml
@@ -876,7 +876,8 @@
                         Grid.Column="1"
                         Width="200"
                         Margin="{StaticResource Margin4}"
-                        HorizontalAlignment="Left" />
+                        HorizontalAlignment="Left"
+                        IsEditable="True" />
 
                     <TextBlock
                         Grid.Row="6"
diff --git a/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml.cs b/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml.cs
index f00dbe36..bceb5c15 100644
--- a/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml.cs
+++ b/v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml.cs
@@ -118,7 +118,7 @@ public partial class OptionSettingWindow : WindowBase<OptionSettingViewModel>
             this.Bind(ViewModel, vm => vm.TunAutoRoute, v => v.togAutoRoute.IsChecked).DisposeWith(disposables);
             this.Bind(ViewModel, vm => vm.TunStrictRoute, v => v.togStrictRoute.IsChecked).DisposeWith(disposables);
             this.Bind(ViewModel, vm => vm.TunStack, v => v.cmbStack.SelectedValue).DisposeWith(disposables);
-            this.Bind(ViewModel, vm => vm.TunMtu, v => v.cmbMtu.SelectedValue).DisposeWith(disposables);
+            this.Bind(ViewModel, vm => vm.TunMtu, v => v.cmbMtu.Text).DisposeWith(disposables);
             this.Bind(ViewModel, vm => vm.TunEnableIPv6Address, v => v.togEnableIPv6Address.IsChecked).DisposeWith(disposables);
             this.Bind(ViewModel, vm => vm.TunIcmpRouting, v => v.cmbIcmpRoutingPolicy.SelectedValue).DisposeWith(disposables);
             this.Bind(ViewModel, vm => vm.TunEnableLegacyProtect, v => v.togEnableLegacyProtect.IsChecked).DisposeWith(disposables);
diff --git a/v2rayN/v2rayN/Views/OptionSettingWindow.xaml b/v2rayN/v2rayN/Views/OptionSettingWindow.xaml
index 0a5208e3..df46d963 100644
--- a/v2rayN/v2rayN/Views/OptionSettingWindow.xaml
+++ b/v2rayN/v2rayN/Views/OptionSettingWindow.xaml
@@ -1141,6 +1141,7 @@
                         Width="200"
                         Margin="{StaticResource Margin8}"
                         HorizontalAlignment="Left"
+                        IsEditable="True"
                         Style="{StaticResource DefComboBox}" />
 
                     <TextBlock