diff --git a/Sources/AppDelegate.swift b/Sources/AppDelegate.swift
index 5cf8caf..d13506c 100644
--- a/Sources/AppDelegate.swift
+++ b/Sources/AppDelegate.swift
@@ -36,6 +36,15 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
         }
     }
 
+    // MARK: - NSApplicationDelegate
+
+    /// Bugger is a menu-bar app: closing a window must not quit it, otherwise
+    /// polling and notifications would stop. Quit only via the Quit button
+    /// or Cmd+Q.
+    func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
+        false
+    }
+
     private func setupStatusItem() {
         statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
         if let button = statusItem.button {