diff --git a/Mac/AppDelegate.swift b/Mac/AppDelegate.swift
index 19b87ccac..212f0a655 100644
--- a/Mac/AppDelegate.swift
+++ b/Mac/AppDelegate.swift
@@ -30,8 +30,7 @@ import Sparkle
 var appDelegate: AppDelegate!
 
 @NSApplicationMain
-class AppDelegate: NSObject, NSApplicationDelegate, NSUserInterfaceValidations, UNUserNotificationCenterDelegate, UnreadCountProvider, SPUStandardUserDriverDelegate, SPUUpdaterDelegate
-{
+final class AppDelegate: NSObject, NSApplicationDelegate, NSUserInterfaceValidations, UNUserNotificationCenterDelegate, UnreadCountProvider, SPUStandardUserDriverDelegate, SPUUpdaterDelegate {
 
 	private struct WindowRestorationIdentifiers {
 		static let mainWindow = "mainWindow"