diff --git a/vcsserver/base.py b/vcsserver/base.py
--- a/vcsserver/base.py
+++ b/vcsserver/base.py
@@ -30,7 +30,7 @@ from vcsserver.lib.exc_tracking import f
 log = logging.getLogger(__name__)
 
 
-class RepoFactory(object):
+class RepoFactory:
     """
     Utility to create instances of repository
 
@@ -84,7 +84,7 @@ def raise_from_original(new_type, org_ex
         del exc_traceback
 
 
-class ArchiveNode(object):
+class ArchiveNode:
     def __init__(self, path, mode, is_link, raw_bytes):
         self.path = path
         self.mode = mode
@@ -176,7 +176,7 @@ def store_archive_in_cache(node_walker, 
         return reader.name
 
 
-class BinaryEnvelope(object):
+class BinaryEnvelope:
     def __init__(self, val):
         self.val = val
 
diff --git a/vcsserver/config/settings_maker.py b/vcsserver/config/settings_maker.py
--- a/vcsserver/config/settings_maker.py
+++ b/vcsserver/config/settings_maker.py
@@ -34,7 +34,7 @@ set_keys = {
 }
 
 
-class SettingsMaker(object):
+class SettingsMaker:
 
     def __init__(self, app_settings):
         self.settings = app_settings
diff --git a/vcsserver/echo_stub/echo_app.py b/vcsserver/echo_stub/echo_app.py
--- a/vcsserver/echo_stub/echo_app.py
+++ b/vcsserver/echo_stub/echo_app.py
@@ -12,7 +12,7 @@ import logging
 log = logging.getLogger(__name__)
 
 
-class EchoApp(object):
+class EchoApp:
 
     def __init__(self, repo_path, repo_name, config):
         self._repo_path = repo_path
@@ -28,7 +28,7 @@ class EchoApp(object):
         return [b"ECHO"]
 
 
-class EchoAppStream(object):
+class EchoAppStream:
 
     def __init__(self, repo_path, repo_name, config):
         self._repo_path = repo_path
diff --git a/vcsserver/echo_stub/remote_wsgi.py b/vcsserver/echo_stub/remote_wsgi.py
--- a/vcsserver/echo_stub/remote_wsgi.py
+++ b/vcsserver/echo_stub/remote_wsgi.py
@@ -15,7 +15,7 @@ from vcsserver import wsgi_app_caller
 log = logging.getLogger(__name__)
 
 
-class GitRemoteWsgi(object):
+class GitRemoteWsgi:
     def handle(self, environ, input_data, *args, **kwargs):
         app = wsgi_app_caller.WSGIAppCaller(
             create_echo_wsgi_app(*args, **kwargs))
@@ -23,7 +23,7 @@ class GitRemoteWsgi(object):
         return app.handle(environ, input_data)
 
 
-class HgRemoteWsgi(object):
+class HgRemoteWsgi:
     def handle(self, environ, input_data, *args, **kwargs):
         app = wsgi_app_caller.WSGIAppCaller(
             create_echo_wsgi_app(*args, **kwargs))
diff --git a/vcsserver/git_lfs/app.py b/vcsserver/git_lfs/app.py
--- a/vcsserver/git_lfs/app.py
+++ b/vcsserver/git_lfs/app.py
@@ -47,7 +47,7 @@ def write_response_error(http_exception,
     return _exception
 
 
-class AuthHeaderRequired(object):
+class AuthHeaderRequired:
     """
     Decorator to check if request has proper auth-header
     """
@@ -94,7 +94,7 @@ def lfs_objects_batch(request):
     if operation not in ('download', 'upload'):
         log.debug('LFS: unsupported operation:%s', operation)
         return write_response_error(
-            HTTPBadRequest, 'unsupported operation mode: `%s`' % operation)
+            HTTPBadRequest, f'unsupported operation mode: `{operation}`')
 
     if 'objects' not in data:
         log.debug('LFS: missing objects data')
@@ -178,7 +178,7 @@ def lfs_objects_oid_download(request):
     if not store.has_oid():
         log.debug('LFS: oid %s does not exists in store', oid)
         return write_response_error(
-            HTTPNotFound, 'requested file with oid `%s` not found in store' % oid)
+            HTTPNotFound, f'requested file with oid `{oid}` not found in store')
 
     # TODO(marcink): support range header ?
     # Range: bytes=0-, `bytes=(\d+)\-.*`
@@ -207,7 +207,7 @@ def lfs_objects_verify(request):
     if not store.has_oid():
         log.debug('LFS: oid %s does not exists in store', oid)
         return write_response_error(
-            HTTPNotFound, 'oid `%s` does not exists in store' % oid)
+            HTTPNotFound, f'oid `{oid}` does not exists in store')
 
     store_size = store.size_oid()
     if store_size != size:
diff --git a/vcsserver/git_lfs/lib.py b/vcsserver/git_lfs/lib.py
--- a/vcsserver/git_lfs/lib.py
+++ b/vcsserver/git_lfs/lib.py
@@ -23,7 +23,7 @@ from collections import OrderedDict
 log = logging.getLogger(__name__)
 
 
-class OidHandler(object):
+class OidHandler:
 
     def __init__(self, store, repo_name, auth, oid, obj_size, obj_data, obj_href,
                  obj_verify_href=None):
@@ -113,7 +113,7 @@ class OidHandler(object):
         return handler(*args, **kwargs)
 
 
-class LFSOidStore(object):
+class LFSOidStore:
 
     def __init__(self, oid, repo, store_location=None):
         self.oid = oid
diff --git a/vcsserver/git_lfs/tests/test_lfs_app.py b/vcsserver/git_lfs/tests/test_lfs_app.py
--- a/vcsserver/git_lfs/tests/test_lfs_app.py
+++ b/vcsserver/git_lfs/tests/test_lfs_app.py
@@ -47,7 +47,7 @@ def http_auth():
     return {'HTTP_AUTHORIZATION': "Basic XXXXX"}
 
 
-class TestLFSApplication(object):
+class TestLFSApplication:
 
     def test_app_wrong_path(self, git_lfs_app):
         git_lfs_app.get('/repo/info/lfs/xxx', status=404)
diff --git a/vcsserver/git_lfs/tests/test_lib.py b/vcsserver/git_lfs/tests/test_lib.py
--- a/vcsserver/git_lfs/tests/test_lib.py
+++ b/vcsserver/git_lfs/tests/test_lib.py
@@ -43,7 +43,7 @@ def oid_handler(lfs_store):
     return oid_handler
 
 
-class TestOidHandler(object):
+class TestOidHandler:
 
     @pytest.mark.parametrize('exec_action', [
         'download',
@@ -120,7 +120,7 @@ class TestOidHandler(object):
         }
 
 
-class TestLFSStore(object):
+class TestLFSStore:
     def test_write_oid(self, lfs_store):
         oid_location = lfs_store.oid_path
 
diff --git a/vcsserver/hook_utils/__init__.py b/vcsserver/hook_utils/__init__.py
--- a/vcsserver/hook_utils/__init__.py
+++ b/vcsserver/hook_utils/__init__.py
@@ -62,7 +62,7 @@ def install_git_hooks(repo_path, bare, e
 
     for h_type, template in [('pre', tmpl_pre), ('post', tmpl_post)]:
         log.debug('Installing git hook in repo %s', repo_path)
-        _hook_file = os.path.join(hooks_path, '%s-receive' % h_type)
+        _hook_file = os.path.join(hooks_path, f'{h_type}-receive')
         _rhodecode_hook = check_rhodecode_hook(_hook_file)
 
         if _rhodecode_hook or force_create:
@@ -114,7 +114,7 @@ def install_svn_hooks(repo_path, executa
 
     for h_type, template in [('pre', tmpl_pre), ('post', tmpl_post)]:
         log.debug('Installing svn hook in repo %s', repo_path)
-        _hook_file = os.path.join(hooks_path, '%s-commit' % h_type)
+        _hook_file = os.path.join(hooks_path, f'{h_type}-commit')
         _rhodecode_hook = check_rhodecode_hook(_hook_file)
 
         if _rhodecode_hook or force_create:
diff --git a/vcsserver/hooks.py b/vcsserver/hooks.py
--- a/vcsserver/hooks.py
+++ b/vcsserver/hooks.py
@@ -40,7 +40,7 @@ from vcsserver.remote.git_remote import 
 log = logging.getLogger(__name__)
 
 
-class HooksHttpClient(object):
+class HooksHttpClient:
     proto = 'msgpack.v1'
     connection = None
 
@@ -88,7 +88,7 @@ class HooksHttpClient(object):
         return headers, msgpack.packb(data)
 
 
-class HooksDummyClient(object):
+class HooksDummyClient:
     def __init__(self, hooks_module):
         self._hooks_module = importlib.import_module(hooks_module)
 
@@ -97,13 +97,13 @@ class HooksDummyClient(object):
             return getattr(hooks, hook_name)(extras)
 
 
-class HooksShadowRepoClient(object):
+class HooksShadowRepoClient:
 
     def __call__(self, hook_name, extras):
         return {'output': '', 'status': 0}
 
 
-class RemoteMessageWriter(object):
+class RemoteMessageWriter:
     """Writer base class."""
     def write(self, message):
         raise NotImplementedError()
@@ -627,7 +627,7 @@ def git_post_receive(unused_repo_path, r
 
             # delete branch case
             elif push_ref['new_rev'] == empty_commit_id:
-                git_revs.append('delete_branch=>%s' % push_ref['name'])
+                git_revs.append(f'delete_branch=>{push_ref["name"]}')
             else:
                 if push_ref['name'] not in branches:
                     branches.append(push_ref['name'])
@@ -659,7 +659,7 @@ def git_post_receive(unused_repo_path, r
         elif type_ == 'tags':
             if push_ref['name'] not in tags:
                 tags.append(push_ref['name'])
-            git_revs.append('tag=>%s' % push_ref['name'])
+            git_revs.append(f'tag=>{push_ref["name"]}')
 
     extras['hook_type'] = 'post_receive'
     extras['commit_ids'] = git_revs
diff --git a/vcsserver/http_main.py b/vcsserver/http_main.py
--- a/vcsserver/http_main.py
+++ b/vcsserver/http_main.py
@@ -112,7 +112,7 @@ def log_max_fd():
         pass
 
 
-class VCS(object):
+class VCS:
     def __init__(self, locale_conf=None, cache_config=None):
         self.locale = locale_conf
         self.cache_config = cache_config
@@ -162,7 +162,7 @@ class VCS(object):
             log.exception('Cannot set locale, not configuring the locale system')
 
 
-class WsgiProxy(object):
+class WsgiProxy:
     def __init__(self, wsgi):
         self.wsgi = wsgi
 
@@ -200,7 +200,7 @@ def not_found(request):
     return {'status': '404 NOT FOUND'}
 
 
-class VCSViewPredicate(object):
+class VCSViewPredicate:
     def __init__(self, val, config):
         self.remotes = val
 
@@ -218,7 +218,7 @@ class VCSViewPredicate(object):
         return backend in self.remotes
 
 
-class HTTPApplication(object):
+class HTTPApplication:
     ALLOWED_EXCEPTIONS = ('KeyError', 'URLError')
 
     remote_wsgi = remote_wsgi
@@ -684,7 +684,7 @@ class HTTPApplication(object):
         raise exception
 
 
-class ResponseFilter(object):
+class ResponseFilter:
 
     def __init__(self, start_response):
         self._start_response = start_response
diff --git a/vcsserver/lib/_vendor/redis_lock/__init__.py b/vcsserver/lib/_vendor/redis_lock/__init__.py
--- a/vcsserver/lib/_vendor/redis_lock/__init__.py
+++ b/vcsserver/lib/_vendor/redis_lock/__init__.py
@@ -102,7 +102,7 @@ class NotExpirable(RuntimeError):
     pass
 
 
-class Lock(object):
+class Lock:
     """
     A Lock context manager implemented via redis SETNX/BLPOP.
     """
diff --git a/vcsserver/lib/_vendor/statsd/base.py b/vcsserver/lib/_vendor/statsd/base.py
--- a/vcsserver/lib/_vendor/statsd/base.py
+++ b/vcsserver/lib/_vendor/statsd/base.py
@@ -29,7 +29,7 @@ def normalize_tags(tag_list):
     return _normalize_tags_with_cache(tuple(tag_list))
 
 
-class StatsClientBase(object):
+class StatsClientBase:
     """A Base class for various statsd clients."""
 
     def close(self):
diff --git a/vcsserver/lib/_vendor/statsd/timer.py b/vcsserver/lib/_vendor/statsd/timer.py
--- a/vcsserver/lib/_vendor/statsd/timer.py
+++ b/vcsserver/lib/_vendor/statsd/timer.py
@@ -9,7 +9,7 @@ def safe_wraps(wrapper, *args, **kwargs)
     return functools.wraps(wrapper, *args, **kwargs)
 
 
-class Timer(object):
+class Timer:
     """A context manager/decorator for statsd.timing()."""
 
     def __init__(self, client, stat, rate=1, tags=None, use_decimals=True, auto_send=True):
diff --git a/vcsserver/lib/rc_cache/backends.py b/vcsserver/lib/rc_cache/backends.py
--- a/vcsserver/lib/rc_cache/backends.py
+++ b/vcsserver/lib/rc_cache/backends.py
@@ -87,7 +87,7 @@ class PickleSerializer:
     )
 
 
-class MsgPackSerializer(object):
+class MsgPackSerializer:
     serializer: None | Serializer = staticmethod(  # type: ignore
         msgpack.packb
     )
@@ -223,7 +223,7 @@ class RedisMsgPackBackend(MsgPackSeriali
 def get_mutex_lock(client, lock_key, lock_timeout, auto_renewal=False):
     from vcsserver.lib._vendor import redis_lock
 
-    class _RedisLockWrapper(object):
+    class _RedisLockWrapper:
         """LockWrapper for redis_lock"""
 
         @classmethod
diff --git a/vcsserver/lib/svnremoterepo.py b/vcsserver/lib/svnremoterepo.py
--- a/vcsserver/lib/svnremoterepo.py
+++ b/vcsserver/lib/svnremoterepo.py
@@ -95,7 +95,7 @@ def _create_auth_baton(pool):
     return core.svn_auth_open(providers, pool)
 
 
-class SubversionRepo(object):
+class SubversionRepo:
     """Wrapper for a Subversion repository.
 
     It uses the SWIG Python bindings, see above for requirements.
@@ -145,7 +145,7 @@ class SubversionRepo(object):
             raise SubversionConnectionException(msg)
 
 
-class svnremoterepo(object):
+class svnremoterepo:
     """ the dumb wrapper for actual Subversion repositories """
 
     def __init__(self, username: bytes = b'', password: bytes = b'', svn_url: bytes = b''):
diff --git a/vcsserver/pygrack.py b/vcsserver/pygrack.py
--- a/vcsserver/pygrack.py
+++ b/vcsserver/pygrack.py
@@ -33,7 +33,7 @@ from vcsserver.str_utils import ascii_by
 log = logging.getLogger(__name__)
 
 
-class FileWrapper(object):
+class FileWrapper:
     """File wrapper that ensures how much data is read from it."""
 
     def __init__(self, fd, content_length):
@@ -61,7 +61,7 @@ class FileWrapper(object):
         )
 
 
-class GitRepository(object):
+class GitRepository:
     """WSGI app for handling Git smart protocol endpoints."""
 
     git_folder_signature = frozenset(('config', 'head', 'info', 'objects', 'refs'))
diff --git a/vcsserver/remote/git_remote.py b/vcsserver/remote/git_remote.py
--- a/vcsserver/remote/git_remote.py
+++ b/vcsserver/remote/git_remote.py
@@ -482,7 +482,7 @@ class GitRemote(RemoteBase):
         o.addheaders = [('User-Agent', 'git/1.7.8.0')]  # fake some git
 
         q = {"service": 'git-upload-pack'}
-        qs = '?%s' % urllib.parse.urlencode(q)
+        qs = f'?{urllib.parse.urlencode(q)}'
         cu = f"{test_uri}{qs}"
         req = urllib.request.Request(cu, None, {})
 
@@ -507,8 +507,7 @@ class GitRemote(RemoteBase):
         else:
             e = None
             raise exceptions.URLError(e)(
-                "url [%s] does not look like an hg repo org_exc: %s"
-                % (obfuscated_uri, e))
+                f"url [{obfuscated_uri}] does not look like an hg repo org_exc: {e}")
 
         return True
 
@@ -1184,7 +1183,7 @@ class GitRemote(RemoteBase):
         """
 
         flags = [
-            '-U%s' % context, '--patch',
+            f'-U{context}', '--patch',
             '--binary',
             '--find-renames',
             '--no-indent-heuristic',
diff --git a/vcsserver/remote/hg_remote.py b/vcsserver/remote/hg_remote.py
--- a/vcsserver/remote/hg_remote.py
+++ b/vcsserver/remote/hg_remote.py
@@ -333,7 +333,7 @@ class HgRemote(RemoteBase):
                     result[attr] = method(wire, commit_id)
                 except KeyError as e:
                     raise exceptions.VcsException(e)(
-                        'Unknown bulk attribute: "%s"' % attr)
+                        f'Unknown bulk attribute: "{attr}"')
             return result
 
         return _bulk_request(repo_id, commit_id, sorted(pre_load))
@@ -499,7 +499,7 @@ class HgRemote(RemoteBase):
 
         q = {"cmd": 'between'}
         q.update({'pairs': "{}-{}".format('0' * 40, '0' * 40)})
-        qs = '?%s' % urllib.parse.urlencode(q)
+        qs = f'?{urllib.parse.urlencode(q)}'
         cu = f"{test_uri}{qs}"
         req = urllib.request.Request(cu, None, {})
 
@@ -528,8 +528,7 @@ class HgRemote(RemoteBase):
             log.warning("URL is not a valid Mercurial repository: %s",
                         obfuscated_uri)
             raise exceptions.URLError(e)(
-                "url [%s] does not look like an hg repo org_exc: %s"
-                % (obfuscated_uri, e))
+                f"url [{obfuscated_uri}] does not look like an hg repo org_exc: {e}")
 
         log.info("URL is a valid Mercurial repository: %s", obfuscated_uri)
         return True
diff --git a/vcsserver/remote/svn_remote.py b/vcsserver/remote/svn_remote.py
--- a/vcsserver/remote/svn_remote.py
+++ b/vcsserver/remote/svn_remote.py
@@ -203,7 +203,7 @@ class SvnRemote(RemoteBase):
         repo_path = wire['path']
         if not self.is_path_valid_repository(wire, repo_path):
             raise Exception(
-                "Path %s is not a valid Subversion repository." % repo_path)
+                f"Path {repo_path} is not a valid Subversion repository.")
 
         cmd = ['svnadmin', 'info', repo_path]
         stdout, stderr = subprocessio.run_command(cmd)
@@ -439,7 +439,7 @@ class SvnRemote(RemoteBase):
         repo_path = wire['path']
         if not self.is_path_valid_repository(wire, repo_path):
             raise Exception(
-                "Path %s is not a valid Subversion repository." % repo_path)
+                f"Path {repo_path} is not a valid Subversion repository.")
 
         username, password, src_url = self.get_url_and_credentials(src_url)
         rdump_cmd = ['svnrdump', 'dump', '--non-interactive',
@@ -477,8 +477,7 @@ class SvnRemote(RemoteBase):
                     src_url, reason))
         if load.returncode != 0:
             raise Exception(
-                'Failed to load the dump of remote repository from %s.' %
-                (src_url, ))
+                f'Failed to load the dump of remote repository from {src_url}.')
 
     def commit(self, wire, message, author, timestamp, updated, removed):
 
@@ -673,7 +672,7 @@ class SvnRemote(RemoteBase):
             file_walker, archive_name_key, kind, mtime, archive_at_path, archive_dir_name, commit_id, cache_config=cache_config)
 
 
-class SvnDiffer(object):
+class SvnDiffer:
     """
     Utility to create diffs based on difflib and the Subversion api
     """
@@ -865,7 +864,7 @@ def authorization_callback_allow_all(roo
     return True
 
 
-class TxnNodeProcessor(object):
+class TxnNodeProcessor:
     """
     Utility to process the change of one node within a transaction root.
 
diff --git a/vcsserver/remote_wsgi.py b/vcsserver/remote_wsgi.py
--- a/vcsserver/remote_wsgi.py
+++ b/vcsserver/remote_wsgi.py
@@ -18,7 +18,7 @@
 from vcsserver import scm_app, wsgi_app_caller
 
 
-class GitRemoteWsgi(object):
+class GitRemoteWsgi:
     def handle(self, environ, input_data, *args, **kwargs):
         app = wsgi_app_caller.WSGIAppCaller(
             scm_app.create_git_wsgi_app(*args, **kwargs))
@@ -26,7 +26,7 @@ class GitRemoteWsgi(object):
         return app.handle(environ, input_data)
 
 
-class HgRemoteWsgi(object):
+class HgRemoteWsgi:
     def handle(self, environ, input_data, *args, **kwargs):
         app = wsgi_app_caller.WSGIAppCaller(
             scm_app.create_hg_wsgi_app(*args, **kwargs))
diff --git a/vcsserver/scm_app.py b/vcsserver/scm_app.py
--- a/vcsserver/scm_app.py
+++ b/vcsserver/scm_app.py
@@ -163,7 +163,7 @@ def create_hg_wsgi_app(repo_path, repo_n
         raise exceptions.RequirementException(e)(e)
 
 
-class GitHandler(object):
+class GitHandler:
     """
     Handler for Git operations like push/pull etc
     """
@@ -209,7 +209,7 @@ def create_git_wsgi_app(repo_path, repo_
     return app
 
 
-class GitLFSHandler(object):
+class GitLFSHandler:
     """
     Handler for Git LFS operations
     """
diff --git a/vcsserver/server.py b/vcsserver/server.py
--- a/vcsserver/server.py
+++ b/vcsserver/server.py
@@ -24,7 +24,7 @@ import time
 log = logging.getLogger(__name__)
 
 
-class VcsServer(object):
+class VcsServer:
     """
     Exposed remote interface of the vcsserver itself.
 
diff --git a/vcsserver/subprocessio.py b/vcsserver/subprocessio.py
--- a/vcsserver/subprocessio.py
+++ b/vcsserver/subprocessio.py
@@ -152,7 +152,7 @@ class InputStreamChunker(threading.Threa
         da.set()  # for cases when done but there was no input.
 
 
-class BufferedGenerator(object):
+class BufferedGenerator:
     """
     Class behaves as a non-blocking, buffered pipe reader.
     Reads chunks of data (through a thread)
@@ -294,7 +294,7 @@ class BufferedGenerator(object):
         return self.data_queue[i]
 
 
-class SubprocessIOChunker(object):
+class SubprocessIOChunker:
     """
     Processor class wrapping handling of subprocess IO.
 
diff --git a/vcsserver/tests/fixture.py b/vcsserver/tests/fixture.py
--- a/vcsserver/tests/fixture.py
+++ b/vcsserver/tests/fixture.py
@@ -21,7 +21,7 @@ import tempfile
 import configparser
 
 
-class ContextINI(object):
+class ContextINI:
     """
     Allows to create a new test.ini file as a copy of existing one with edited
     data. If existing file is not present, it creates a new one. Example usage::
diff --git a/vcsserver/tests/test_git.py b/vcsserver/tests/test_git.py
--- a/vcsserver/tests/test_git.py
+++ b/vcsserver/tests/test_git.py
@@ -47,7 +47,7 @@ def test_discover_git_version(git_remote
     assert version
 
 
-class TestGitFetch(object):
+class TestGitFetch:
     def setup_method(self):
         self.mock_repo = Mock()
         factory = Mock()
@@ -99,7 +99,7 @@ class TestGitFetch(object):
             assert remote_refs == sample_refs
 
 
-class TestReraiseSafeExceptions(object):
+class TestReraiseSafeExceptions:
 
     def test_method_decorated_with_reraise_safe_exceptions(self):
         factory = Mock()
@@ -134,7 +134,7 @@ class TestReraiseSafeExceptions(object):
         assert exc_info.value._vcs_kind == expected_type
 
 
-class TestDulwichRepoWrapper(object):
+class TestDulwichRepoWrapper:
     def test_calls_close_on_delete(self):
         isdir_patcher = patch('dulwich.repo.os.path.isdir', return_value=True)
         with patch.object(git_remote.Repo, 'close') as close_mock:
@@ -147,7 +147,7 @@ class TestDulwichRepoWrapper(object):
             close_mock.assert_called_once_with()
 
 
-class TestGitFactory(object):
+class TestGitFactory:
     def test_create_repo_returns_dulwich_wrapper(self):
 
         with patch('vcsserver.lib.rc_cache.region_meta.dogpile_cache_regions') as mock:
diff --git a/vcsserver/tests/test_hg.py b/vcsserver/tests/test_hg.py
--- a/vcsserver/tests/test_hg.py
+++ b/vcsserver/tests/test_hg.py
@@ -27,7 +27,7 @@ from vcsserver import exceptions, hgcomp
 from vcsserver.remote import hg_remote
 
 
-class TestDiff(object):
+class TestDiff:
     def test_raising_safe_exception_when_lookup_failed(self):
 
         factory = Mock()
@@ -44,7 +44,7 @@ class TestDiff(object):
             assert exc_info.value._vcs_kind == 'lookup'
 
 
-class TestReraiseSafeExceptions(object):
+class TestReraiseSafeExceptions:
     original_traceback = None
 
     def test_method_decorated_with_reraise_safe_exceptions(self):
diff --git a/vcsserver/tests/test_hooks.py b/vcsserver/tests/test_hooks.py
--- a/vcsserver/tests/test_hooks.py
+++ b/vcsserver/tests/test_hooks.py
@@ -121,7 +121,7 @@ def test_git_post_pull_is_disabled():
         hooks.git_post_pull({'hooks': ['push']}) == hooks.HookResponse(0, ''))
 
 
-class TestGetHooksClient(object):
+class TestGetHooksClient:
 
     def test_returns_http_client_when_protocol_matches(self):
         hooks_uri = 'localhost:8000'
@@ -146,7 +146,7 @@ class TestGetHooksClient(object):
         assert result._hooks_module == fake_module
 
 
-class TestHooksHttpClient(object):
+class TestHooksHttpClient:
     def test_init_sets_hooks_uri(self):
         uri = 'localhost:3000'
         client = hooks.HooksHttpClient(uri)
@@ -182,7 +182,7 @@ class TestHooksHttpClient(object):
         assert result == expected_result
 
 
-class TestHooksDummyClient(object):
+class TestHooksDummyClient:
     def test_init_imports_hooks_module(self):
         hooks_module_name = 'rhodecode.fake.module'
         hooks_module = mock.MagicMock()
@@ -224,7 +224,7 @@ class MirrorHttpHandler(BaseHTTPRequestH
         self.wfile.write(body)
 
 
-class MirrorHttpServer(object):
+class MirrorHttpServer:
     ip_address = '127.0.0.1'
     port = 0
 
diff --git a/vcsserver/tests/test_install_hooks.py b/vcsserver/tests/test_install_hooks.py
--- a/vcsserver/tests/test_install_hooks.py
+++ b/vcsserver/tests/test_install_hooks.py
@@ -27,7 +27,7 @@ from vcsserver.str_utils import safe_byt
 from vcsserver.utils import AttributeDict
 
 
-class TestCheckRhodecodeHook(object):
+class TestCheckRhodecodeHook:
 
     def test_returns_false_when_hook_file_is_wrong_found(self, tmpdir):
         hook = os.path.join(str(tmpdir), 'fake_hook_file.py')
@@ -55,7 +55,7 @@ class TestCheckRhodecodeHook(object):
         assert result is expected_result
 
 
-class BaseInstallHooks(object):
+class BaseInstallHooks:
     HOOK_FILES = ()
 
     def _check_hook_file_mode(self, file_path):
diff --git a/vcsserver/tests/test_pygrack.py b/vcsserver/tests/test_pygrack.py
--- a/vcsserver/tests/test_pygrack.py
+++ b/vcsserver/tests/test_pygrack.py
@@ -72,7 +72,7 @@ def test_invalid_endpoint_returns_403(py
 def test_pre_pull_hook_fails_with_sideband(pygrack_app, sideband):
     request = ''.join([
         '0054want 74730d410fcb6603ace96f1dc55ea6196122532d ',
-        'multi_ack %s ofs-delta\n' % sideband,
+        f'multi_ack {sideband} ofs-delta\n',
         '0000',
         '0009done\n',
     ])
diff --git a/vcsserver/tests/test_subprocessio.py b/vcsserver/tests/test_subprocessio.py
--- a/vcsserver/tests/test_subprocessio.py
+++ b/vcsserver/tests/test_subprocessio.py
@@ -25,7 +25,7 @@ from vcsserver import subprocessio
 from vcsserver.str_utils import ascii_bytes
 
 
-class FileLikeObj(object):  # pragma: no cover
+class FileLikeObj:  # pragma: no cover
 
     def __init__(self, data: bytes, size):
         chunks = size // len(data)
diff --git a/vcsserver/tests/test_svn.py b/vcsserver/tests/test_svn.py
--- a/vcsserver/tests/test_svn.py
+++ b/vcsserver/tests/test_svn.py
@@ -23,7 +23,7 @@ import sys
 from vcsserver.str_utils import ascii_bytes
 
 
-class MockPopen(object):
+class MockPopen:
     def __init__(self, stderr):
         self.stdout = io.BytesIO(b'')
         self.stderr = io.BytesIO(stderr)
diff --git a/vcsserver/tweens/request_wrapper.py b/vcsserver/tweens/request_wrapper.py
--- a/vcsserver/tweens/request_wrapper.py
+++ b/vcsserver/tweens/request_wrapper.py
@@ -55,7 +55,7 @@ def get_headers_call_context(environ, st
         raise ValueError('Expected header HTTP_X_RC_VCS_STREAM_CALL_CONTEXT not found')
 
 
-class RequestWrapperTween(object):
+class RequestWrapperTween:
     def __init__(self, handler, registry):
         self.handler = handler
         self.registry = registry
diff --git a/vcsserver/vcs_base.py b/vcsserver/vcs_base.py
--- a/vcsserver/vcs_base.py
+++ b/vcsserver/vcs_base.py
@@ -18,7 +18,7 @@
 from vcsserver.lib import rc_cache
 
 
-class RemoteBase(object):
+class RemoteBase:
     EMPTY_COMMIT = '0' * 40
 
     def _region(self, wire):
diff --git a/vcsserver/wsgi_app_caller.py b/vcsserver/wsgi_app_caller.py
--- a/vcsserver/wsgi_app_caller.py
+++ b/vcsserver/wsgi_app_caller.py
@@ -50,7 +50,7 @@ def _complete_environ(environ, input_dat
 
 
 # pylint: disable=too-few-public-methods
-class _StartResponse(object):
+class _StartResponse:
     """Save the arguments of a start_response call."""
 
     __slots__ = ['status', 'headers', 'content']
@@ -76,7 +76,7 @@ class _StartResponse(object):
         self.content.append(content)
 
 
-class WSGIAppCaller(object):
+class WSGIAppCaller:
     """Calls a WSGI app."""
 
     def __init__(self, app):