diff --git a/src/DiffEngineTray/Settings/OptionsFormLauncher.cs b/src/DiffEngineTray/Settings/OptionsFormLauncher.cs
index a3f4e607..c43122af 100644
--- a/src/DiffEngineTray/Settings/OptionsFormLauncher.cs
+++ b/src/DiffEngineTray/Settings/OptionsFormLauncher.cs
@@ -6,7 +6,11 @@
 static class OptionsFormLauncher
 {
     static OptionsForm? instance;
-    static EventHandler formOnClosed = Form_Closed;
+    static EventHandler formOnClosed = (_, _) =>
+    {
+        instance!.Closed -= formOnClosed;
+        instance = null;
+    };
 
     public static async Task Launch(KeyRegister keyRegister, Tracker tracker)
     {
@@ -23,12 +27,6 @@ public static async Task Launch(KeyRegister keyRegister, Tracker tracker)
         form.ShowDialog();
     }
 
-    static void Form_Closed(object? sender, EventArgs e)
-    {
-        instance!.Closed -= formOnClosed;
-        instance = null;
-    }
-
     static async Task<IReadOnlyList<string>> Save(KeyRegister keyRegister, Tracker tracker, Settings settings)
     {
         if (!settings.IsValidate(out var errors))