diff --git a/nvchecker/source/android_sdk.py b/nvchecker/source/android_sdk.py
index fc4a079..06caacb 100644
--- a/nvchecker/source/android_sdk.py
+++ b/nvchecker/source/android_sdk.py
@@ -20,7 +20,7 @@ for repo in _ANDROID_REPO_MANIFESTS.keys():
   _repo_manifests_locks[repo] = Lock()
 
 async def _get_repo_manifest(repo):
-  with (await _repo_manifests_locks[repo]):
+  async with _repo_manifests_locks[repo]:
     if repo in _repo_manifests_cache:
       return _repo_manifests_cache[repo]
 
diff --git a/tests/conftest.py b/tests/conftest.py
index b8b2afa..6398d7d 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -8,58 +8,58 @@ from nvchecker.get_version import get_version as _get_version
 from nvchecker.core import Source
 
 class TestSource(Source):
-    def __init__(self, future, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self._future = future
+  def __init__(self, future, *args, **kwargs):
+    super().__init__(*args, **kwargs)
+    self._future = future
 
-    def on_update(self, name, version, oldver):
-        self._future.set_result(version)
+  def on_update(self, name, version, oldver):
+    self._future.set_result(version)
 
-    def on_no_result(self, name):
-        self._future.set_result(None)
+  def on_no_result(self, name):
+    self._future.set_result(None)
 
-    def on_exception(self, name, exc):
-        self._future.set_exception(exc)
+  def on_exception(self, name, exc):
+    self._future.set_exception(exc)
 
 @pytest.fixture(scope="module")
 async def run_source():
-    async def __call__(conf):
-        future = asyncio.Future()
-        file = io.StringIO(conf)
-        file.name = '<StringIO>'
+  async def __call__(conf):
+    future = asyncio.Future()
+    file = io.StringIO(conf)
+    file.name = '<StringIO>'
 
-        s = TestSource(future, file)
-        await s.check()
-        return await future
+    s = TestSource(future, file)
+    await s.check()
+    return await future
 
-    return __call__
+  return __call__
 
 @pytest.fixture(scope="module")
 async def get_version():
-    async def __call__(name, config):
+  async def __call__(name, config):
 
-        if isinstance(config, dict):
-            _config = configparser.ConfigParser(dict_type=dict, allow_no_value=True)
-            _config.read_dict({name: config})
-            config = _config[name]
+    if isinstance(config, dict):
+      _config = configparser.ConfigParser(dict_type=dict, allow_no_value=True)
+      _config.read_dict({name: config})
+      config = _config[name]
 
-        return await _get_version(name, config)
+    return await _get_version(name, config)
 
-    return __call__
+  return __call__
 
 @pytest.fixture(scope="module")
 def event_loop(request):
-    """Override pytest-asyncio's event_loop fixture,
-       Don't create an instance of the default event loop for each test case.
-    """
-    loop = asyncio.get_event_loop()
-    yield loop
+  """Override pytest-asyncio's event_loop fixture,
+     Don't create an instance of the default event loop for each test case.
+  """
+  loop = asyncio.get_event_loop()
+  yield loop
 
 @pytest.fixture(scope="module")
 def raise_on_logger_msg():
-    def proc(logger, method_name, event_dict):
-        if method_name in ('warn', 'error'):
-            raise RuntimeError(event_dict['event'])
-        return event_dict['event']
+  def proc(logger, method_name, event_dict):
+    if method_name in ('warn', 'error'):
+      raise RuntimeError(event_dict['event'])
+    return event_dict['event']
 
-    structlog.configure([proc])
+  structlog.configure([proc])