diff --git a/server/tests/integration/collab.test.ts b/server/tests/integration/collab.test.ts
index bf3a9de67..578bdf023 100644
--- a/server/tests/integration/collab.test.ts
+++ b/server/tests/integration/collab.test.ts
@@ -74,6 +74,10 @@ beforeAll(async () => {
   nestApp = await buildApp();
   app = nestApp.getHttpAdapter().getInstance();
   if (!fs.existsSync(uploadsDir)) fs.mkdirSync(uploadsDir, { recursive: true });
+  // Warm the notificationService module: notifyCollab does a fire-and-forget
+  // dynamic import of it, and a cold load can otherwise race the worker
+  // teardown ("Cannot load ... after the environment was torn down").
+  await import('../../src/services/notificationService');
 });
 
 beforeEach(() => {
diff --git a/server/tests/integration/packing.test.ts b/server/tests/integration/packing.test.ts
index c637aaa8e..a3cf3a9df 100644
--- a/server/tests/integration/packing.test.ts
+++ b/server/tests/integration/packing.test.ts
@@ -58,6 +58,10 @@ beforeAll(async () => {
   runMigrations(testDb);
   nestApp = await buildApp();
   app = nestApp.getHttpAdapter().getInstance();
+  // Warm the notificationService module: notifyTagged does a fire-and-forget
+  // dynamic import of it, and a cold load can otherwise race the worker
+  // teardown ("Cannot load ... after the environment was torn down").
+  await import('../../src/services/notificationService');
 });
 
 beforeEach(() => {
diff --git a/server/tests/integration/trips.test.ts b/server/tests/integration/trips.test.ts
index 0535e2eb1..17d24c3c0 100644
--- a/server/tests/integration/trips.test.ts
+++ b/server/tests/integration/trips.test.ts
@@ -67,6 +67,10 @@ beforeAll(async () => {
   runMigrations(testDb);
   nestApp = await buildApp();
   app = nestApp.getHttpAdapter().getInstance();
+  // Warm the notificationService module: notifyInvite does a fire-and-forget
+  // dynamic import of it, and a cold load can otherwise race the worker
+  // teardown ("Cannot load ... after the environment was torn down").
+  await import('../../src/services/notificationService');
 });
 beforeEach(() => {
   resetTestDb(testDb);
diff --git a/server/tests/integration/vacay.test.ts b/server/tests/integration/vacay.test.ts
index 8e8167472..42fde5593 100644
--- a/server/tests/integration/vacay.test.ts
+++ b/server/tests/integration/vacay.test.ts
@@ -75,6 +75,10 @@ beforeAll(async () => {
   runMigrations(testDb);
   nestApp = await buildApp();
   app = nestApp.getHttpAdapter().getInstance();
+  // Warm the notificationService module: sendInvite/shareCalendar do a
+  // fire-and-forget dynamic import of it, and a cold load can otherwise race
+  // the worker teardown ("Cannot load ... after the environment was torn down").
+  await import('../../src/services/notificationService');
 });
 
 beforeEach(() => {
diff --git a/server/tests/setup.ts b/server/tests/setup.ts
index a6ecb75d4..e07dc1212 100644
--- a/server/tests/setup.ts
+++ b/server/tests/setup.ts
@@ -1,9 +1,25 @@
 // Global test setup — runs before every test file.
 // Environment variables must be set before any module import so that
-// config.ts, database.ts, etc. pick them up at import time.
+// config.ts, database.ts, etc. pick them up at import time. (Importing from
+// 'vitest' itself is safe: it is externalized and pulls in no app modules.)
+import { afterEach } from 'vitest';
 
 // Fixed encryption key (64 hex chars = 32 bytes) for at-rest crypto in tests
 process.env.ENCRYPTION_KEY = 'a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6a7b8c9d0e1f2a3b4c5d6a7b8c9d0e1f2';
 process.env.NODE_ENV = 'test';
 process.env.COOKIE_SECURE = 'false';
 process.env.LOG_LEVEL = 'error'; // suppress info/debug logs in test output
+
+// Several services fire notification sends as unawaited dynamic-import chains
+// (`import('…/notificationService').then(({ send }) => send(…).catch(…))`).
+// Give those chains one macrotask turn to settle after every test, while the
+// suite's DB and the worker environment are still alive — otherwise the last
+// test in a file can leave the chain pending into worker teardown ("Cannot
+// load ... after the environment was torn down"). Under the default "stack"
+// hook order this afterEach runs after each test's own afterEach and before
+// the suite's afterAll, i.e. before any afterAll closes its test DB.
+// setImmediate is captured up front because some suites install fake timers.
+const realSetImmediate = globalThis.setImmediate;
+afterEach(async () => {
+  await new Promise((resolve) => realSetImmediate(resolve));
+});
diff --git a/server/tests/unit/nest/trips.service.test.ts b/server/tests/unit/nest/trips.service.test.ts
index d10a8d34f..f8b4ac23d 100644
--- a/server/tests/unit/nest/trips.service.test.ts
+++ b/server/tests/unit/nest/trips.service.test.ts
@@ -1,4 +1,4 @@
-import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { describe, it, expect, vi, beforeAll, beforeEach } from 'vitest';
 
 const { dbMock } = vi.hoisted(() => {
   const stmt = { get: vi.fn(() => ({ id: 42 })), all: vi.fn(() => []), run: vi.fn() };
@@ -12,6 +12,8 @@ import type { PermissionsService } from '../../../src/nest/permissions/permissio
 
 const { broadcast } = vi.hoisted(() => ({ broadcast: vi.fn() }));
 vi.mock('../../../src/websocket', () => ({ broadcast }));
+// notifyInvite fires a notification via a dynamic import — keep it out of unit scope
+vi.mock('../../../src/services/notificationService', () => ({ send: vi.fn().mockResolvedValue(undefined) }));
 const checkPermission = vi.fn(() => true);
 const permissionsStub = { checkPermission } as unknown as PermissionsService;
 
@@ -48,6 +50,12 @@ const reservationsStub = { list: () => [] } as unknown as ReservationsService;
 const daysStub = { list: () => ({ days: [1] }), listAccommodations: () => [] } as unknown as DaysService;
 function svc() { return new TripsService(new DatabaseService(dbConn), todoStub, packingStub, filesStub, reservationsStub, daysStub, permissionsStub, budgetStub); }
 beforeEach(() => vi.clearAllMocks());
+beforeAll(async () => {
+  // Warm the (mocked) notificationService module: notifyInvite does a
+  // fire-and-forget dynamic import of it, and a cold load can otherwise race
+  // the worker teardown ("Cannot load ... after the environment was torn down").
+  await import('../../../src/services/notificationService');
+});
 
 describe('TripsService (wrapper delegation + bundle/copy/notify helpers)', () => {
   it('delegates the simple wrappers to tripService', async () => {