diff --git a/apps/desktop/src/components/WindowControls.test.tsx b/apps/desktop/src/components/WindowControls.test.tsx
new file mode 100644
index 000000000..e73c8186e
--- /dev/null
+++ b/apps/desktop/src/components/WindowControls.test.tsx
@@ -0,0 +1,50 @@
+// @vitest-environment jsdom
+import { act } from 'react';
+import { createRoot, type Root } from 'react-dom/client';
+import { afterEach, beforeEach, expect, it, vi } from 'vitest';
+import { WindowControls } from './WindowControls';
+
+const native = vi.hoisted(() => ({
+  maximized: false,
+  resized: undefined as (() => void) | undefined,
+  unlisten: vi.fn(),
+  toggleMaximize: vi.fn(),
+}));
+
+vi.mock('@tauri-apps/api/core', () => ({ isTauri: () => true }));
+vi.mock('@tauri-apps/api/window', () => ({ getCurrentWindow: () => ({
+  isMaximized: async () => native.maximized,
+  onResized: async (handler: () => void) => { native.resized = handler; return native.unlisten; },
+  toggleMaximize: native.toggleMaximize,
+  minimize: vi.fn(),
+  close: vi.fn(),
+}) }));
+
+let root: Root;
+let host: HTMLDivElement;
+beforeEach(() => {
+  vi.stubGlobal('IS_REACT_ACT_ENVIRONMENT', true);
+  native.maximized = false;
+  native.resized = undefined;
+  native.unlisten.mockClear();
+  native.toggleMaximize.mockReset().mockImplementation(async () => { native.maximized = !native.maximized; });
+  host = document.createElement('div');
+  root = createRoot(host);
+});
+afterEach(async () => { await act(async () => root.unmount()); vi.unstubAllGlobals(); });
+
+it('shows the restore icon after maximizing and tracks external window resizing', async () => {
+  await act(async () => root.render(<WindowControls onError={error => { throw Error(error); }} t={key => key} />));
+  const button = host.querySelector<HTMLButtonElement>('[aria-label="windowMenu.maximize"]')!;
+  expect(button.getAttribute('aria-pressed')).toBe('false');
+  expect(button.querySelector('.lucide-square')).not.toBeNull();
+
+  await act(async () => button.click());
+  expect(button.getAttribute('aria-pressed')).toBe('true');
+  expect(button.querySelector('.lucide-copy')).not.toBeNull();
+
+  await act(async () => { native.maximized = false; native.resized?.(); });
+  expect(button.getAttribute('aria-pressed')).toBe('false');
+  expect(button.querySelector('.lucide-square')).not.toBeNull();
+  expect(native.unlisten).not.toHaveBeenCalled();
+});
diff --git a/apps/desktop/src/components/WindowControls.tsx b/apps/desktop/src/components/WindowControls.tsx
index 96de88fc5..e4529afa6 100644
--- a/apps/desktop/src/components/WindowControls.tsx
+++ b/apps/desktop/src/components/WindowControls.tsx
@@ -1,17 +1,49 @@
+import { useEffect, useState } from "react";
+import { isTauri } from "@tauri-apps/api/core";
 import { getCurrentWindow } from "@tauri-apps/api/window";
-import { Minus, Square, X } from "lucide-react";
+import { Copy, Minus, Square, X } from "lucide-react";
 import type { Translate } from "../i18n";
 
 export function WindowControls({ onError, t }: { onError: (message: string) => void; t: Translate }) {
+  const [maximized, setMaximized] = useState(false);
+
+  useEffect(() => {
+    if (!isTauri()) return;
+    const appWindow = getCurrentWindow();
+    let active = true;
+    let unlisten: (() => void) | undefined;
+    const refresh = () => {
+      void appWindow.isMaximized().then(value => {
+        if (active) setMaximized(value);
+      }).catch((error: unknown) => {
+        if (active) onError(String(error));
+      });
+    };
+    refresh();
+    void appWindow.onResized(refresh).then(stop => {
+      if (active) unlisten = stop;
+      else stop();
+    }).catch((error: unknown) => {
+      if (active) onError(String(error));
+    });
+    return () => { active = false; unlisten?.(); };
+  }, [onError]);
+
   const run = (action: "minimize" | "toggleMaximize" | "close") => {
-    void getCurrentWindow()[action]().catch((error: unknown) => onError(String(error)));
+    void getCurrentWindow()[action]().then(() => {
+      if (action === "toggleMaximize") {
+        void getCurrentWindow().isMaximized().then(setMaximized).catch((error: unknown) => onError(String(error)));
+      }
+    }).catch((error: unknown) => onError(String(error)));
   };
   return (
     <div className="window-controls">
       <button type="button" className="window-control" aria-label={t("windowMenu.minimize")}
         onClick={() => run("minimize")}><Minus size={16} /></button>
       <button type="button" className="window-control" aria-label={t("windowMenu.maximize")}
-        onClick={() => run("toggleMaximize")}><Square size={13} /></button>
+        aria-pressed={maximized} onClick={() => run("toggleMaximize")}>
+        {maximized ? <Copy size={15} /> : <Square size={13} />}
+      </button>
       <button type="button" className="window-control window-control-close" aria-label={t("windowMenu.close")}
         onClick={() => run("close")}><X size={17} /></button>
     </div>