diff --git a/examples/connect.py b/examples/connect.py
index 1d4b86ad8..09a9cbef1 100644
--- a/examples/connect.py
+++ b/examples/connect.py
@@ -36,7 +36,7 @@ config = loader.OpenStackConfig()
 cloud = openstack.connect(cloud=TEST_CLOUD)
 
 
-class Opts(object):
+class Opts:
     def __init__(self, cloud_name='devstack-admin', debug=False):
         self.cloud = cloud_name
         self.debug = debug
diff --git a/openstack/_services_mixin.py b/openstack/_services_mixin.py
index eb58e83b8..75c1d19e7 100644
--- a/openstack/_services_mixin.py
+++ b/openstack/_services_mixin.py
@@ -20,7 +20,7 @@ from openstack.orchestration import orchestration_service
 from openstack.workflow import workflow_service
 
 
-class ServicesMixin(object):
+class ServicesMixin:
 
     identity = identity_service.IdentityService(service_type='identity')
 
diff --git a/openstack/baremetal/v1/_common.py b/openstack/baremetal/v1/_common.py
index 8fcf7b579..e37c7b73a 100644
--- a/openstack/baremetal/v1/_common.py
+++ b/openstack/baremetal/v1/_common.py
@@ -68,7 +68,7 @@ CONFIG_DRIVE_DICT_VERSION = '1.56'
 """API version in which configdrive can be a dictionary."""
 
 
-class ListMixin(object):
+class ListMixin:
 
     @classmethod
     def list(cls, session, details=False, **params):
diff --git a/openstack/baremetal/v1/node.py b/openstack/baremetal/v1/node.py
index 5c034e723..8ef4edff4 100644
--- a/openstack/baremetal/v1/node.py
+++ b/openstack/baremetal/v1/node.py
@@ -18,7 +18,7 @@ from openstack import resource
 from openstack import utils
 
 
-class ValidationResult(object):
+class ValidationResult:
     """Result of a single interface validation.
 
     :ivar result: Result of a validation, ``True`` for success, ``False`` for
diff --git a/openstack/cloud/_normalize.py b/openstack/cloud/_normalize.py
index 97a27fa0b..4cbcd9f85 100644
--- a/openstack/cloud/_normalize.py
+++ b/openstack/cloud/_normalize.py
@@ -139,7 +139,7 @@ def _pop_or_get(resource, key, default, strict):
         return resource.get(key, default)
 
 
-class Normalizer(object):
+class Normalizer:
     '''Mix-in class to provide the normalization functions.
 
     This is in a separate class just for on-disk source code organization
diff --git a/openstack/cloud/_utils.py b/openstack/cloud/_utils.py
index 9a6a8cf0b..bb82a165b 100644
--- a/openstack/cloud/_utils.py
+++ b/openstack/cloud/_utils.py
@@ -667,7 +667,7 @@ def generate_patches_from_kwargs(operation, **kwargs):
     return sorted(patches)
 
 
-class FileSegment(object):
+class FileSegment:
     """File-like object to pass to requests."""
 
     def __init__(self, filename, offset, length):
diff --git a/openstack/cloud/inventory.py b/openstack/cloud/inventory.py
index 8905ce0a7..32a26821b 100644
--- a/openstack/cloud/inventory.py
+++ b/openstack/cloud/inventory.py
@@ -22,7 +22,7 @@ from openstack.cloud import _utils
 __all__ = ['OpenStackInventory']
 
 
-class OpenStackInventory(object):
+class OpenStackInventory:
 
     # Put this here so the capability can be detected with hasattr on the class
     extra_config = None
diff --git a/openstack/cloud/openstackcloud.py b/openstack/cloud/openstackcloud.py
index 2e821238a..fefdd9ba1 100755
--- a/openstack/cloud/openstackcloud.py
+++ b/openstack/cloud/openstackcloud.py
@@ -48,7 +48,7 @@ DEFAULT_MAX_FILE_SIZE = _object_store.DEFAULT_MAX_FILE_SIZE
 OBJECT_CONTAINER_ACLS = _object_store.OBJECT_CONTAINER_ACLS
 
 
-class _OpenStackCloudMixin(object):
+class _OpenStackCloudMixin:
     """Represent a connection to an OpenStack Cloud.
 
     OpenStackCloud is the entry point for all cloud operations, regardless
@@ -126,7 +126,7 @@ class _OpenStackCloudMixin(object):
             def _fake_invalidate(unused):
                 pass
 
-            class _FakeCache(object):
+            class _FakeCache:
                 def invalidate(self):
                     pass
 
diff --git a/openstack/compute/v2/metadata.py b/openstack/compute/v2/metadata.py
index 906dc7213..0d8ad2f12 100644
--- a/openstack/compute/v2/metadata.py
+++ b/openstack/compute/v2/metadata.py
@@ -15,7 +15,7 @@ from openstack import exceptions
 from openstack import utils
 
 
-class MetadataMixin(object):
+class MetadataMixin:
 
     def _metadata(self, method, key=None, clear=False, delete=False,
                   metadata=None):
diff --git a/openstack/config/_util.py b/openstack/config/_util.py
index cdd6737e8..c77aaf235 100644
--- a/openstack/config/_util.py
+++ b/openstack/config/_util.py
@@ -45,7 +45,7 @@ def merge_clouds(old_dict, new_dict):
     return ret
 
 
-class VersionRequest(object):
+class VersionRequest:
     def __init__(
         self,
         version=None,
diff --git a/openstack/config/cloud_region.py b/openstack/config/cloud_region.py
index 41bcc9d5d..8f03d5386 100644
--- a/openstack/config/cloud_region.py
+++ b/openstack/config/cloud_region.py
@@ -201,7 +201,7 @@ def from_conf(conf, session=None, service_types=None, **kwargs):
         session=session, config=config_dict, **kwargs)
 
 
-class CloudRegion(object):
+class CloudRegion:
     # TODO(efried): Doc the rest of the kwargs
     """The configuration for a Region of an OpenStack Cloud.
 
diff --git a/openstack/config/loader.py b/openstack/config/loader.py
index 09e916c37..a86433f31 100644
--- a/openstack/config/loader.py
+++ b/openstack/config/loader.py
@@ -127,7 +127,7 @@ def _fix_argv(argv):
                 options=','.join(overlap)))
 
 
-class OpenStackConfig(object):
+class OpenStackConfig:
 
     # These two attribute are to allow os-client-config to plumb in its
     # local versions for backwards compat.
diff --git a/openstack/format.py b/openstack/format.py
index 94fd310fe..7e586709d 100644
--- a/openstack/format.py
+++ b/openstack/format.py
@@ -11,7 +11,7 @@
 # under the License.
 
 
-class Formatter(object):
+class Formatter:
 
     @classmethod
     def serialize(cls, value):
diff --git a/openstack/image/_download.py b/openstack/image/_download.py
index 0c50bffb2..21c6ffe77 100644
--- a/openstack/image/_download.py
+++ b/openstack/image/_download.py
@@ -24,7 +24,7 @@ def _verify_checksum(md5, checksum):
                 "checksum mismatch: %s != %s" % (checksum, digest))
 
 
-class DownloadMixin(object):
+class DownloadMixin:
 
     def download(self, session, stream=False, output=None, chunk_size=1024):
         """Download the data contained in an image"""
diff --git a/openstack/image/image_signer.py b/openstack/image/image_signer.py
index 19c6ec965..23d294811 100644
--- a/openstack/image/image_signer.py
+++ b/openstack/image/image_signer.py
@@ -28,7 +28,7 @@ HASH_METHODS = {
 }
 
 
-class ImageSigner(object):
+class ImageSigner:
     """Image file signature generator.
 
     Generates signatures for files using a specified private key file.
diff --git a/openstack/image/iterable_chunked_file.py b/openstack/image/iterable_chunked_file.py
index d887ace5b..3b9d9569d 100644
--- a/openstack/image/iterable_chunked_file.py
+++ b/openstack/image/iterable_chunked_file.py
@@ -12,7 +12,7 @@
 #
 
 
-class IterableChunkedFile(object):
+class IterableChunkedFile:
     """File object chunk iterator using yield.
 
     Represents a local file as an iterable object by splitting the file
diff --git a/openstack/resource.py b/openstack/resource.py
index cf9d9a476..b102549a4 100644
--- a/openstack/resource.py
+++ b/openstack/resource.py
@@ -82,7 +82,7 @@ def _convert_type(value, data_type, list_type=None):
         return data_type(value)
 
 
-class _BaseComponent(object):
+class _BaseComponent:
 
     # The name this component is being tracked as in the Resource
     key = None
@@ -257,7 +257,7 @@ class _ComponentManager(collections.MutableMapping):
             self._dirty = set()
 
 
-class _Request(object):
+class _Request:
     """Prepared components that go into a KSA request"""
 
     def __init__(self, url, body, headers):
@@ -266,7 +266,7 @@ class _Request(object):
         self.headers = headers
 
 
-class QueryParameters(object):
+class QueryParameters:
 
     def __init__(self, *names, **mappings):
         """Create a dict of accepted query parameters
@@ -1862,7 +1862,7 @@ class Resource(dict):
             "No %s found for %s" % (cls.__name__, name_or_id))
 
 
-class TagMixin(object):
+class TagMixin:
 
     _tag_query_parameters = {
         'tags': 'tags',
diff --git a/openstack/service_description.py b/openstack/service_description.py
index 2aad61a6d..223a166d3 100644
--- a/openstack/service_description.py
+++ b/openstack/service_description.py
@@ -27,7 +27,7 @@ _logger = _log.setup_logging('openstack')
 _service_type_manager = os_service_types.ServiceTypes()
 
 
-class _ServiceDisabledProxyShim(object):
+class _ServiceDisabledProxyShim:
     def __init__(self, service_type, reason):
         self.service_type = service_type
         self.reason = reason
@@ -39,7 +39,7 @@ class _ServiceDisabledProxyShim(object):
                 service_type=self.service_type, reason=self.reason or ''))
 
 
-class ServiceDescription(object):
+class ServiceDescription:
 
     #: Dictionary of supported versions and proxy classes for that version
     supported_versions = None
diff --git a/openstack/tests/fakes.py b/openstack/tests/fakes.py
index 9fae3c7f5..af1bbe235 100644
--- a/openstack/tests/fakes.py
+++ b/openstack/tests/fakes.py
@@ -282,7 +282,7 @@ def make_fake_port(address, node_id=None, port_id=None):
         node_id=node_id))
 
 
-class FakeFloatingIP(object):
+class FakeFloatingIP:
     def __init__(self, id, pool, ip, fixed_ip, instance_id):
         self.id = id
         self.pool = pool
@@ -345,7 +345,7 @@ def make_fake_hypervisor(id, name):
     }))
 
 
-class FakeVolume(object):
+class FakeVolume:
     def __init__(
             self, id, status, name, attachments=[],
             size=75):
@@ -363,7 +363,7 @@ class FakeVolume(object):
         self.metadata = {}
 
 
-class FakeVolumeSnapshot(object):
+class FakeVolumeSnapshot:
     def __init__(
             self, id, status, name, description, size=75):
         self.id = id
@@ -376,7 +376,7 @@ class FakeVolumeSnapshot(object):
         self.metadata = {}
 
 
-class FakeMachine(object):
+class FakeMachine:
     def __init__(self, id, name=None, driver=None, driver_info=None,
                  chassis_uuid=None, instance_info=None, instance_uuid=None,
                  properties=None, reservation=None, last_error=None,
@@ -394,7 +394,7 @@ class FakeMachine(object):
         self.provision_state = provision_state
 
 
-class FakeMachinePort(object):
+class FakeMachinePort:
     def __init__(self, id, address, node_id):
         self.uuid = id
         self.address = address
@@ -443,7 +443,7 @@ def make_fake_nova_security_group(id, name, description, rules):
     }))
 
 
-class FakeNovaSecgroupRule(object):
+class FakeNovaSecgroupRule:
     def __init__(self, id, from_port=None, to_port=None, ip_protocol=None,
                  cidr=None, parent_group_id=None):
         self.id = id
@@ -455,13 +455,13 @@ class FakeNovaSecgroupRule(object):
         self.parent_group_id = parent_group_id
 
 
-class FakeHypervisor(object):
+class FakeHypervisor:
     def __init__(self, id, hostname):
         self.id = id
         self.hypervisor_hostname = hostname
 
 
-class FakeZone(object):
+class FakeZone:
     def __init__(self, id, name, type_, email, description,
                  ttl, masters):
         self.id = id
@@ -473,7 +473,7 @@ class FakeZone(object):
         self.masters = masters
 
 
-class FakeRecordset(object):
+class FakeRecordset:
     def __init__(self, zone, id, name, type_, description,
                  ttl, records):
         self.zone = zone
diff --git a/openstack/tests/functional/image/v2/test_image.py b/openstack/tests/functional/image/v2/test_image.py
index badd31fc5..3635b6a72 100644
--- a/openstack/tests/functional/image/v2/test_image.py
+++ b/openstack/tests/functional/image/v2/test_image.py
@@ -18,7 +18,7 @@ TEST_IMAGE_NAME = 'Test Image'
 
 class TestImage(base.BaseFunctionalTest):
 
-    class ImageOpts(object):
+    class ImageOpts:
         def __init__(self):
             self.image_api_version = '2'
 
diff --git a/openstack/tests/unit/cloud/test_meta.py b/openstack/tests/unit/cloud/test_meta.py
index 0de6620d3..e925c63dd 100644
--- a/openstack/tests/unit/cloud/test_meta.py
+++ b/openstack/tests/unit/cloud/test_meta.py
@@ -24,13 +24,13 @@ PUBLIC_V4 = '192.0.2.99'
 PUBLIC_V6 = '2001:0db8:face:0da0:face::0b00:1c'  # rfc3849
 
 
-class FakeConfig(object):
+class FakeConfig:
     def get_region_name(self, service_type=None):
         # TODO(efried): Validate service_type?
         return 'test-region'
 
 
-class FakeCloud(object):
+class FakeCloud:
     config = FakeConfig()
     name = 'test-name'
     private = False
@@ -942,10 +942,10 @@ class TestMeta(base.TestCase):
 
     def test_obj_list_to_munch(self):
         """Test conversion of a list of objects to a list of dictonaries"""
-        class obj0(object):
+        class obj0:
             value = 0
 
-        class obj1(object):
+        class obj1:
             value = 1
 
         list = [obj0, obj1]
diff --git a/openstack/tests/unit/cloud/test_zone.py b/openstack/tests/unit/cloud/test_zone.py
index 3bea3fb71..145e04a26 100644
--- a/openstack/tests/unit/cloud/test_zone.py
+++ b/openstack/tests/unit/cloud/test_zone.py
@@ -26,7 +26,7 @@ zone_dict = {
 }
 
 
-class ZoneTestWrapper(object):
+class ZoneTestWrapper:
 
     def __init__(self, ut, attrs):
         self.remote_res = attrs
diff --git a/openstack/tests/unit/compute/v2/test_server.py b/openstack/tests/unit/compute/v2/test_server.py
index 6baf3c45c..e48266d8e 100644
--- a/openstack/tests/unit/compute/v2/test_server.py
+++ b/openstack/tests/unit/compute/v2/test_server.py
@@ -806,7 +806,7 @@ class TestServer(base.TestCase):
     def test_live_migrate_no_force(self):
         sot = server.Server(**EXAMPLE)
 
-        class FakeEndpointData(object):
+        class FakeEndpointData:
             min_microversion = None
             max_microversion = None
         self.sess.get_endpoint_data.return_value = FakeEndpointData()
@@ -822,7 +822,7 @@ class TestServer(base.TestCase):
     def test_live_migrate_no_microversion_force_true(self):
         sot = server.Server(**EXAMPLE)
 
-        class FakeEndpointData(object):
+        class FakeEndpointData:
             min_microversion = None
             max_microversion = None
         self.sess.get_endpoint_data.return_value = FakeEndpointData()
@@ -848,7 +848,7 @@ class TestServer(base.TestCase):
     def test_live_migrate_25(self):
         sot = server.Server(**EXAMPLE)
 
-        class FakeEndpointData(object):
+        class FakeEndpointData:
             min_microversion = '2.1'
             max_microversion = '2.25'
         self.sess.get_endpoint_data.return_value = FakeEndpointData()
@@ -872,7 +872,7 @@ class TestServer(base.TestCase):
     def test_live_migrate_25_default_block(self):
         sot = server.Server(**EXAMPLE)
 
-        class FakeEndpointData(object):
+        class FakeEndpointData:
             min_microversion = '2.1'
             max_microversion = '2.25'
         self.sess.get_endpoint_data.return_value = FakeEndpointData()
@@ -896,7 +896,7 @@ class TestServer(base.TestCase):
     def test_live_migrate_30(self):
         sot = server.Server(**EXAMPLE)
 
-        class FakeEndpointData(object):
+        class FakeEndpointData:
             min_microversion = '2.1'
             max_microversion = '2.30'
         self.sess.get_endpoint_data.return_value = FakeEndpointData()
@@ -920,7 +920,7 @@ class TestServer(base.TestCase):
     def test_live_migrate_30_force(self):
         sot = server.Server(**EXAMPLE)
 
-        class FakeEndpointData(object):
+        class FakeEndpointData:
             min_microversion = '2.1'
             max_microversion = '2.30'
         self.sess.get_endpoint_data.return_value = FakeEndpointData()
diff --git a/openstack/tests/unit/image/v2/test_image.py b/openstack/tests/unit/image/v2/test_image.py
index 4bc95baf6..0086c640f 100644
--- a/openstack/tests/unit/image/v2/test_image.py
+++ b/openstack/tests/unit/image/v2/test_image.py
@@ -95,7 +95,7 @@ def calculate_md5_checksum(data):
     return checksum.hexdigest()
 
 
-class FakeResponse(object):
+class FakeResponse:
     def __init__(self, response, status_code=200, headers=None, reason=None):
         self.body = response
         self.content = response
diff --git a/openstack/tests/unit/image/v2/test_proxy.py b/openstack/tests/unit/image/v2/test_proxy.py
index 20e35d750..5392c7381 100644
--- a/openstack/tests/unit/image/v2/test_proxy.py
+++ b/openstack/tests/unit/image/v2/test_proxy.py
@@ -27,7 +27,7 @@ from openstack.tests.unit import test_proxy_base
 EXAMPLE = fake_image.EXAMPLE
 
 
-class FakeResponse(object):
+class FakeResponse:
     def __init__(self, response, status_code=200, headers=None):
         self.body = response
         self.status_code = status_code
diff --git a/openstack/tests/unit/test_proxy.py b/openstack/tests/unit/test_proxy.py
index 46c9ff8be..3cd7b0ed2 100644
--- a/openstack/tests/unit/test_proxy.py
+++ b/openstack/tests/unit/test_proxy.py
@@ -137,7 +137,7 @@ class TestProxyPrivate(base.TestCase):
         # of that same behavior to let us check that `new` gets
         # called with the expected arguments.
 
-        class Fake(object):
+        class Fake:
             call = {}
 
             @classmethod
diff --git a/openstack/tests/unit/test_resource.py b/openstack/tests/unit/test_resource.py
index 6d327a1a8..67fd7c863 100644
--- a/openstack/tests/unit/test_resource.py
+++ b/openstack/tests/unit/test_resource.py
@@ -24,7 +24,7 @@ from openstack import resource
 from openstack.tests.unit import base
 
 
-class FakeResponse(object):
+class FakeResponse:
     def __init__(self, response, status_code=200, headers=None):
         self.body = response
         self.status_code = status_code
@@ -74,7 +74,7 @@ class TestComponent(base.TestCase):
     def test_get_name_None(self):
         name = "name"
 
-        class Parent(object):
+        class Parent:
             _example = {name: None}
 
         instance = Parent()
@@ -87,7 +87,7 @@ class TestComponent(base.TestCase):
     def test_get_default(self):
         expected_result = 123
 
-        class Parent(object):
+        class Parent:
             _example = {}
 
         instance = Parent()
@@ -104,7 +104,7 @@ class TestComponent(base.TestCase):
         name = "name"
         expected_result = 123
 
-        class Parent(object):
+        class Parent:
             _example = {name: expected_result}
 
         instance = Parent()
@@ -119,7 +119,7 @@ class TestComponent(base.TestCase):
         name = "name"
         value = "123"
 
-        class Parent(object):
+        class Parent:
             _example = {name: value}
 
         instance = Parent()
@@ -134,7 +134,7 @@ class TestComponent(base.TestCase):
         value = "123"
         expected_result = "one hundred twenty three"
 
-        class Parent(object):
+        class Parent:
             _example = {name: value}
 
         class FakeFormatter(format.Formatter):
@@ -154,7 +154,7 @@ class TestComponent(base.TestCase):
         name = "name"
         expected_value = "123"
 
-        class Parent(object):
+        class Parent:
             _example = {}
 
         instance = Parent()
@@ -167,7 +167,7 @@ class TestComponent(base.TestCase):
     def test_set_name_typed(self):
         expected_value = "123"
 
-        class Parent(object):
+        class Parent:
             _example = {}
 
         instance = Parent()
@@ -177,7 +177,7 @@ class TestComponent(base.TestCase):
         # instance that would allow us to call `assert_called_once_with` to
         # ensure that we're sending the value through the type.
         # Instead, we use this tiny version of a similar thing.
-        class FakeType(object):
+        class FakeType:
             calls = []
 
             def __init__(self, arg):
@@ -192,7 +192,7 @@ class TestComponent(base.TestCase):
     def test_set_name_formatter(self):
         expected_value = "123"
 
-        class Parent(object):
+        class Parent:
             _example = {}
 
         instance = Parent()
@@ -220,7 +220,7 @@ class TestComponent(base.TestCase):
         name = "name"
         expected_value = "123"
 
-        class Parent(object):
+        class Parent:
             _example = {name: expected_value}
 
         instance = Parent()
@@ -235,7 +235,7 @@ class TestComponent(base.TestCase):
         name = "name"
         expected_value = "123"
 
-        class Parent(object):
+        class Parent:
             _example = {"what": expected_value}
 
         instance = Parent()
diff --git a/openstack/utils.py b/openstack/utils.py
index d893d6fc0..962113fd7 100644
--- a/openstack/utils.py
+++ b/openstack/utils.py
@@ -75,7 +75,7 @@ def get_string_format_keys(fmt_string, old_style=True):
     use the old style string formatting.
     """
     if old_style:
-        class AccessSaver(object):
+        class AccessSaver:
             def __init__(self):
                 self.keys = []
 
@@ -192,7 +192,7 @@ def maximum_supported_microversion(adapter, client_maximum):
     return discover.version_to_string(result)
 
 
-class TinyDAG(object):
+class TinyDAG:
     """Tiny DAG
 
     Bases on the Kahn's algorithm, and enables parallel visiting of the nodes
diff --git a/tools/print-services.py b/tools/print-services.py
index b4c664957..73dd3d09f 100644
--- a/tools/print-services.py
+++ b/tools/print-services.py
@@ -71,7 +71,7 @@ def make_names():
     for imp in sorted(imports):
         print(imp)
     print('\n')
-    print("class ServicesMixin(object):\n")
+    print("class ServicesMixin:\n")
     for service in services:
         if service:
             print("    {service}".format(service=service))
diff --git a/tox.ini b/tox.ini
index 3e6f1bfd0..e8809b843 100644
--- a/tox.ini
+++ b/tox.ini
@@ -107,12 +107,13 @@ commands =
 # The following are ignored on purpose. It's not super worth it to fix them.
 # However, if you feel strongly about it, patches will be accepted to fix them
 # if they fix ALL of the occurances of one and only one of them.
+# H238 New Style Classes are the default in Python3
 # H306 Is about alphabetical imports - there's a lot to fix.
 # H4 Are about docstrings and there's just a huge pile of pre-existing issues.
 # W503 Is supposed to be off by default but in the latest pycodestyle isn't.
 #      Also, both openstacksdk and Donald Knuth disagree with the rule. Line
 #      breaks should occur before the binary operator for readability.
-ignore = H306,H4,W503
+ignore = H238,H306,H4,W503
 show-source = True
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,openstack/_services_mixin.py