diff --git a/Flow.Launcher/ViewModel/SettingWindowViewModel.cs b/Flow.Launcher/ViewModel/SettingWindowViewModel.cs
index ad63220c7..1134a81b8 100644
--- a/Flow.Launcher/ViewModel/SettingWindowViewModel.cs
+++ b/Flow.Launcher/ViewModel/SettingWindowViewModel.cs
@@ -1,3 +1,4 @@
+using System;
 using Flow.Launcher.Infrastructure.UserSettings;
 using Flow.Launcher.Plugin;