diff --git a/apps/desktop/e2e/quit.spec.ts b/apps/desktop/e2e/quit.spec.ts
index 9ff393d..c143963 100644
--- a/apps/desktop/e2e/quit.spec.ts
+++ b/apps/desktop/e2e/quit.spec.ts
@@ -48,3 +48,40 @@ test('quitting DevHub stops the whole process tree of running scripts', async ({
   await app.close()
   await expect.poll(() => tree.filter(isAlive), { timeout: 15_000 }).toEqual([])
 })
+
+// Logout, shutdown and `systemctl --user stop` send SIGTERM first; Windows has no equivalent.
+test.describe('SIGTERM', () => {
+  test.skip(process.platform === 'win32', 'POSIX signals only')
+
+  test('quits DevHub gracefully when nothing is running', async ({ launchDevhub }) => {
+    const { app } = await launchDevhub()
+    const child = app.process()
+    const exited = new Promise((resolve) => child.once('exit', resolve))
+
+    child.kill('SIGTERM')
+    await exited
+    // A graceful quit exits normally; the default handler would report the signal instead.
+    expect({ code: child.exitCode, signal: child.signalCode }).toEqual({ code: 0, signal: null })
+  })
+
+  test('stops the process tree of running scripts', async ({ launchDevhub, createProject }) => {
+    const dir = await createProject('server', {
+      'package.json': packageJson({ serve: 'node server.js' }),
+      'server.js': serverScript
+    })
+    const { app, page } = await launchDevhub()
+    await addProjectViaApi(page, dir)
+    await page.getByRole('button', { name: '运行 serve' }).click()
+    await expect(page.locator('.xterm-rows')).toContainText('serving')
+    const pids = pidsSchema.parse(JSON.parse(await readFile(join(dir, 'pids.json'), 'utf8')))
+    const tree = [pids.parent, pids.child]
+    expect(tree.every(isAlive)).toBe(true)
+
+    const child = app.process()
+    const exited = new Promise((resolve) => child.once('exit', resolve))
+    child.kill('SIGTERM')
+    await exited
+    expect(child.exitCode).toBe(0)
+    await expect.poll(() => tree.filter(isAlive), { timeout: 15_000 }).toEqual([])
+  })
+})
diff --git a/apps/desktop/src/main/index.ts b/apps/desktop/src/main/index.ts
index 012a85c..4fb863a 100644
--- a/apps/desktop/src/main/index.ts
+++ b/apps/desktop/src/main/index.ts
@@ -84,7 +84,11 @@ if (!app.requestSingleInstanceLock()) {
     const timeout = new Promise((resolve) => setTimeout(resolve, disposeTimeoutMs))
     void Promise.race([core.dispose(), timeout])
       .catch((error: unknown) => console.error('[quit] failed to stop runs', error))
-      .finally(() => app.quit())
+      // Not directly: with nothing to stop, dispose settles in the microtasks Node drains as
+      // this handler returns. On SIGTERM Electron calls Quit() with no JS on the stack, so a
+      // nested quit would run inside it and be overwritten by this prevented one, leaving
+      // DevHub running with every window closed (#39).
+      .finally(() => setImmediate(() => app.quit()))
   })
 
   // With "keep in tray" the window only hides, so this fires only for "quit on close".
diff --git a/docs/PROGRESS.md b/docs/PROGRESS.md
index 9f6de2f..05ffc56 100644
--- a/docs/PROGRESS.md
+++ b/docs/PROGRESS.md
@@ -50,7 +50,7 @@ M4-3 Android：
 桌面修复：
 
 - #22 已完成：启动的子进程不再直接继承 DevHub 的环境：Windows 从注册表修复并补全 PATH（更新后经 Explorer 重启时 `%NVM_HOME%` 未展开、找不到 pnpm），Linux 捕获交互登录 shell 的环境（从桌面启动时缺少 `.bashrc` 中的 nvm）（ADR 0024）。
-- #39 待开始：Linux 上收到 SIGTERM 不退出（#8 中发现），关机或注销时可能留下孤儿进程。
+- #39 已完成，待合并：Linux 上收到 SIGTERM 不退出（#8 中发现）。没有运行中的脚本时，`before-quit` 里的 `app.quit()` 会在 Electron 处理信号的 `Quit()` 内部重入，退出状态被外层覆盖，窗口关闭后进程挂住；改为推迟到下一轮事件循环。E2E 覆盖 SIGTERM 退出与停止进程树（Windows 跳过）。
 - #42 已完成，待合并：远程服务启动时端口被占用（更新后旧进程尚未退出）会重试约 15 秒，期间状态显示「正在重试」；修改设置时的冲突仍立即报告。
 
 桌面 MVP 发布：