diff --git a/ceilometer/hacking/checks.py b/ceilometer/hacking/checks.py
index f092921883..daeeef65bc 100644
--- a/ceilometer/hacking/checks.py
+++ b/ceilometer/hacking/checks.py
@@ -38,7 +38,7 @@ def no_log_warn(logical_line):
     C301
     """
     if logical_line.startswith('LOG.warn('):
-        yield(0, 'C301 Use LOG.warning() rather than LOG.warn()')
+        yield (0, 'C301 Use LOG.warning() rather than LOG.warn()')
 
 
 @core.flake8ext
@@ -52,5 +52,5 @@ def no_os_popen(logical_line):
     """
 
     if 'os.popen(' in logical_line:
-        yield(0, 'C302 Deprecated library function os.popen(). '
-                 'Replace it using subprocess module. ')
+        yield (0, 'C302 Deprecated library function os.popen(). '
+                  'Replace it using subprocess module. ')
diff --git a/ceilometer/tests/unit/polling/test_dynamic_pollster.py b/ceilometer/tests/unit/polling/test_dynamic_pollster.py
index f85af7292e..15c590e828 100644
--- a/ceilometer/tests/unit/polling/test_dynamic_pollster.py
+++ b/ceilometer/tests/unit/polling/test_dynamic_pollster.py
@@ -1618,7 +1618,7 @@ class TestDynamicPollster(base.BaseTestCase):
         request_args = pollster.definitions.sample_gatherer\
             .create_request_arguments(pollster.definitions.configurations)
 
-        self.assertTrue("headers" in request_args)
+        self.assertIn("headers", request_args)
         self.assertEqual(2, len(request_args["headers"]))
 
         self.assertEqual(['header1', 'header2'],
@@ -1629,7 +1629,7 @@ class TestDynamicPollster(base.BaseTestCase):
                          list(map(lambda h: list(h.values())[0],
                                   request_args["headers"])))
 
-        self.assertTrue("authenticated" not in request_args)
+        self.assertNotIn("authenticated", request_args)
 
     def test_create_request_arguments_PollsterSampleGatherer(self):
         pollster_definition = copy.deepcopy(
@@ -1644,8 +1644,8 @@ class TestDynamicPollster(base.BaseTestCase):
         request_args = pollster.definitions.sample_gatherer\
             .create_request_arguments(pollster.definitions.configurations)
 
-        self.assertTrue("headers" in request_args)
-        self.assertTrue("authenticated" in request_args)
+        self.assertIn("headers", request_args)
+        self.assertIn("authenticated", request_args)
         self.assertTrue(request_args["authenticated"])
 
         self.assertEqual(3, len(request_args["headers"]))
@@ -1667,8 +1667,8 @@ class TestDynamicPollster(base.BaseTestCase):
             pollster.definitions.sample_gatherer.create_request_arguments(
                 pollster.definitions.configurations)
 
-        self.assertTrue("headers" not in request_args)
-        self.assertTrue("authenticated" in request_args)
+        self.assertNotIn("headers", request_args)
+        self.assertIn("authenticated", request_args)
         self.assertTrue(request_args["authenticated"])
 
     @mock.patch('keystoneclient.v2_0.client.Client')
diff --git a/tox.ini b/tox.ini
index 12137fc3b8..e0f47ba9bb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,8 +33,9 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:pep8]
-deps = hacking>=3.0.1,<=3.1.0
-       doc8
+deps =
+    hacking>=6.1.0,<6.2.0
+    doc8
 commands =
     flake8
     doc8 {posargs}