diff --git a/Apps/WhatIsMyDnsApp/App.cs b/Apps/WhatIsMyDnsApp/App.cs
index fe370120..3c5f0427 100644
--- a/Apps/WhatIsMyDnsApp/App.cs
+++ b/Apps/WhatIsMyDnsApp/App.cs
@@ -1,6 +1,6 @@
 /*
 Technitium DNS Server
-Copyright (C) 2023  Shreyas Zare (shreyas@technitium.com)
+Copyright (C) 2024  Shreyas Zare (shreyas@technitium.com)
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -27,7 +27,7 @@ using TechnitiumLibrary.Net.Dns.ResourceRecords;
 
 namespace WhatIsMyDns
 {
-    public class App : IDnsApplication, IDnsAppRecordRequestHandler
+    public sealed class App : IDnsApplication, IDnsAppRecordRequestHandler
     {
         #region IDisposable