diff --git a/apps/server/src/core/auth/services/token.service.spec.ts b/apps/server/src/core/auth/services/token.service.spec.ts
index a5f5d655a7..c167be35da 100644
--- a/apps/server/src/core/auth/services/token.service.spec.ts
+++ b/apps/server/src/core/auth/services/token.service.spec.ts
@@ -1,12 +1,34 @@
+jest.mock('../../../common/helpers', () => ({
+  isUserDisabled: () => false,
+}));
+
 import { Test, TestingModule } from '@nestjs/testing';
+import { JwtModule } from '@nestjs/jwt';
+import * as jwt from 'jsonwebtoken';
 import { TokenService } from './token.service';
+import { EnvironmentService } from '../../../integrations/environment/environment.service';
+import { createMockUser } from '../../../test-utils/test-helpers';
 
 describe('TokenService', () => {
   let service: TokenService;
 
   beforeEach(async () => {
     const module: TestingModule = await Test.createTestingModule({
-      providers: [TokenService],
+      imports: [
+        // Mirror production: a module-level expiresIn default exists, intended
+        // for short-lived access tokens. generateApiToken must NOT inherit it.
+        JwtModule.register({
+          secret: 'test-secret',
+          signOptions: { expiresIn: '90d', issuer: 'Docmost' },
+        }),
+      ],
+      providers: [
+        TokenService,
+        {
+          provide: EnvironmentService,
+          useValue: { getAppSecret: () => 'test-secret' },
+        },
+      ],
     }).compile();
 
     service = module.get<TokenService>(TokenService);
@@ -15,4 +37,61 @@ describe('TokenService', () => {
   it('should be defined', () => {
     expect(service).toBeDefined();
   });
+
+  describe('generateApiToken', () => {
+    const user = createMockUser();
+
+    it('uses a long-lived exp (~100y) when no expiresIn is supplied, instead of inheriting the 90d module default', async () => {
+      const before = Math.floor(Date.now() / 1000);
+
+      const token = await service.generateApiToken({
+        apiKeyId: 'key-id-1',
+        user,
+        workspaceId: user.workspaceId,
+      });
+
+      const decoded = jwt.decode(token) as {
+        exp?: number;
+        iat?: number;
+        type?: string;
+        apiKeyId?: string;
+        sub?: string;
+        workspaceId?: string;
+      } | null;
+      expect(decoded).not.toBeNull();
+      expect(decoded!.type).toBe('api_key');
+      expect(decoded!.apiKeyId).toBe('key-id-1');
+      expect(decoded!.sub).toBe(user.id);
+      expect(decoded!.workspaceId).toBe(user.workspaceId);
+
+      // Must NOT be the leaky 90d module default (the bug). Anything past one
+      // year out is fine; we use 100y in production.
+      const ninetyDaysSeconds = 90 * 24 * 60 * 60;
+      const oneYearSeconds = 365 * 24 * 60 * 60;
+      expect(decoded!.iat).toBeDefined();
+      expect(decoded!.exp).toBeDefined();
+      expect(decoded!.iat!).toBeGreaterThanOrEqual(before);
+      const ttl = decoded!.exp! - decoded!.iat!;
+      expect(ttl).toBeGreaterThan(oneYearSeconds);
+      expect(ttl).not.toBe(ninetyDaysSeconds);
+    });
+
+    it('respects an explicit numeric expiresIn (seconds) when supplied', async () => {
+      const before = Math.floor(Date.now() / 1000);
+
+      const token = await service.generateApiToken({
+        apiKeyId: 'key-id-2',
+        user,
+        workspaceId: user.workspaceId,
+        expiresIn: 3600,
+      });
+
+      const decoded = jwt.decode(token) as { exp?: number; iat?: number } | null;
+      expect(decoded).not.toBeNull();
+      expect(decoded!.exp).toBeDefined();
+      expect(decoded!.iat).toBeDefined();
+      expect(decoded!.exp! - decoded!.iat!).toBe(3600);
+      expect(decoded!.iat!).toBeGreaterThanOrEqual(before);
+    });
+  });
 });
diff --git a/apps/server/src/core/auth/services/token.service.ts b/apps/server/src/core/auth/services/token.service.ts
index b9035ba36f..d9edec1c36 100644
--- a/apps/server/src/core/auth/services/token.service.ts
+++ b/apps/server/src/core/auth/services/token.service.ts
@@ -112,7 +112,9 @@ export class TokenService {
       type: JwtType.API_KEY,
     };
 
-    return this.jwtService.sign(payload, expiresIn ? { expiresIn } : {});
+    // due to the default value of 90 days, if no expiry is provided
+    // 100y are set as a maximum length
+    return this.jwtService.sign(payload, { expiresIn: expiresIn ?? '100y' });
   }
 
   async verifyJwt(token: string, tokenType: string) {