diff --git a/tests/unit/test_lipsync_gpu_async_task.py b/tests/unit/test_lipsync_gpu_async_task.py
index 2ab3a9404..00b8ece1f 100644
--- a/tests/unit/test_lipsync_gpu_async_task.py
+++ b/tests/unit/test_lipsync_gpu_async_task.py
@@ -263,21 +263,21 @@ def test_cancelled_gpu_task_does_not_fallback_mediakit(monkeypatch):
 
     fake_gpu_svc = MagicMock()
     fake_gpu_svc.wait_for_result.return_value = gpu_task
+    gpu_service_cls = MagicMock(return_value=fake_gpu_svc)
 
     fake_db = MagicMock()
     fake_db.query.return_value.filter_by.return_value.first.return_value = job
-    # wait_for_result 直接被 mock 到 gpu_svc，这里仅备查
 
-    monkeypatch.setattr(
-        "app.services.gpu_lipsync_service.GpuLipsyncService",
-        MagicMock(return_value=fake_gpu_svc),
-    )
-    session_factory = MagicMock()
-    session_factory.return_value = fake_db
-    # _get_db_session 优先用 worker_app.db（pytest 环境可导入），两个都 patch
-    monkeypatch.setattr("worker_app.db.SessionLocal", session_factory)
-    monkeypatch.setattr("app.db.SessionLocal", session_factory)
-    monkeypatch.setattr("app.tasks.lipsync_gpu.logger", MagicMock())
+    # 直接替换 sys.modules 里的 gpu_lipsync_service 模块（全量跑时它可能已被
+    # 其他测试换成 MagicMock），保证任务函数内 from...import 一定拿到我们的类；
+    # 并替换 _get_db_session 绕开 worker_app / app.db 两条 import 分支。
+    import sys
+    from types import SimpleNamespace
+
+    fake_mod = SimpleNamespace(GpuLipsyncService=gpu_service_cls)
+    monkeypatch.setitem(sys.modules, "app.services.gpu_lipsync_service", fake_mod)
+    monkeypatch.setattr(task_mod, "_get_db_session", lambda: fake_db)
+    monkeypatch.setattr(task_mod, "logger", MagicMock())
 
     task_mod.lipsync_gpu_process_async.run("job-1", "u1", "gpu-task-1")
 
@@ -285,3 +285,4 @@ def test_cancelled_gpu_task_does_not_fallback_mediakit(monkeypatch):
     assert not str(job.mediakit_task_id).startswith("mk-")
     fake_db.commit.assert_called()
     fake_gpu_svc.wait_for_result.assert_called_once()
+    gpu_service_cls.assert_called_once_with(fake_db)