diff --git a/contrib/helpers.py b/contrib/helpers.py
index 77532b1..fd81ae1 100644
--- a/contrib/helpers.py
+++ b/contrib/helpers.py
@@ -39,7 +39,7 @@ def goTo(path):
     return False
 
 
-class Author(object):
+class Author():
     def __init__(self, name, count, email):
         self.name = name
         self.count = count
@@ -55,7 +55,7 @@ class Author(object):
         return self.email
 
 
-class Git(object):
+class Git():
     @staticmethod
     def getShortlog(ref):
         shortlog = ""
@@ -199,7 +199,7 @@ class Git(object):
         chdir(topLevel)
 
 
-class OfflineimapInfo(object):
+class OfflineimapInfo():
     def getVersion(self):
         cmd = shlex.split("./offlineimap.py --version")
         return run(cmd).rstrip().decode(FS_ENCODING)
@@ -209,7 +209,7 @@ class OfflineimapInfo(object):
 
 
 
-class User(object):
+class User():
     """Interact with the user."""
 
     @staticmethod
@@ -235,7 +235,7 @@ class User(object):
         return False
 
 
-class Tester(object):
+class Tester():
     def __init__(self, name, email, feedback):
         self.name = name
         self.email = email
@@ -264,7 +264,7 @@ class Tester(object):
         self.feedback = not self.feedback
 
 
-class Testers(object):
+class Testers():
     def __init__(self):
         self.testers = None
         self._read()
diff --git a/contrib/release.py b/contrib/release.py
index 81d9873..7bbf55e 100755
--- a/contrib/release.py
+++ b/contrib/release.py
@@ -89,7 +89,7 @@ Have fun! ,-)
 """
 
 
-class State(object):
+class State():
     def __init__(self):
         self.master = None
         self.next = None
@@ -129,7 +129,7 @@ class State(object):
                 goTo('..')
 
 
-class Changelog(object):
+class Changelog():
     def __init__(self):
         self.shouldUsePrevious = False
 
@@ -214,7 +214,7 @@ class Changelog(object):
         return dict_Content
 
 
-class Announce(object):
+class Announce():
     def __init__(self, version):
         self.fd = open(ANNOUNCE_FILE, 'w')
         self.version = version
@@ -258,7 +258,7 @@ Pip:
         self.fd.close()
 
 
-class Website(object):
+class Website():
     def updateUploads(self):
         req = ("add new archive to uploads/ on the website? "
                "(warning: checksums will change if it already exists)")
@@ -333,7 +333,7 @@ Then, commit and push changes of the website.""".format(SPHINXBUILD, DOCSDIR)))
         return branchName
 
 
-class Release(object):
+class Release():
     def __init__(self):
         self.state = State()
         self.offlineimapInfo = OfflineimapInfo()
diff --git a/contrib/tested-by.py b/contrib/tested-by.py
index c37f3dd..ff949a9 100755
--- a/contrib/tested-by.py
+++ b/contrib/tested-by.py
@@ -14,7 +14,7 @@ import argparse
 from helpers import CACHEDIR, EDITOR, Testers, User, Git
 
 
-class App(object):
+class App():
     def __init__(self):
         self.args = None
         self.testers = Testers()
diff --git a/offlineimap/CustomConfig.py b/offlineimap/CustomConfig.py
index 5737993..689270b 100644
--- a/offlineimap/CustomConfig.py
+++ b/offlineimap/CustomConfig.py
@@ -157,7 +157,7 @@ def CustomConfigDefault():
     pass
 
 
-class ConfigHelperMixin(object):
+class ConfigHelperMixin():
     """Allow comfortable retrieving of config values pertaining
     to a section.
 
diff --git a/offlineimap/folder/Base.py b/offlineimap/folder/Base.py
index 5aceacc..c89b191 100644
--- a/offlineimap/folder/Base.py
+++ b/offlineimap/folder/Base.py
@@ -26,7 +26,7 @@ from offlineimap.error import OfflineImapError
 import offlineimap.accounts
 
 
-class BaseFolder(object):
+class BaseFolder():
     __hash__ = None
 
     def __init__(self, name, repository):
diff --git a/offlineimap/folder/LocalStatusSQLite.py b/offlineimap/folder/LocalStatusSQLite.py
index 02647eb..62fb03f 100644
--- a/offlineimap/folder/LocalStatusSQLite.py
+++ b/offlineimap/folder/LocalStatusSQLite.py
@@ -25,7 +25,7 @@ import six
 from .Base import BaseFolder
 
 
-class DatabaseFileLock(object):
+class DatabaseFileLock():
     """Lock at database file level."""
 
     def __init__(self):
diff --git a/offlineimap/imaplibutil.py b/offlineimap/imaplibutil.py
index d056b25..655e720 100644
--- a/offlineimap/imaplibutil.py
+++ b/offlineimap/imaplibutil.py
@@ -32,7 +32,7 @@ from offlineimap.ui import getglobalui
 from offlineimap.virtual_imaplib2 import IMAP4, IMAP4_SSL, InternalDate
 
 
-class UsefulIMAPMixIn(object):
+class UsefulIMAPMixIn():
     def __getselectedfolder(self):
         if self.state == 'SELECTED':
             return self.mailbox
diff --git a/offlineimap/imapserver.py b/offlineimap/imapserver.py
index 91d9174..973deb2 100644
--- a/offlineimap/imapserver.py
+++ b/offlineimap/imapserver.py
@@ -42,7 +42,7 @@ except ImportError:
     have_gss = False
 
 
-class IMAPServer(object):
+class IMAPServer():
     """Initializes all variables from an IMAPRepository() instance
 
     Various functions, such as acquireconnection() return an IMAP4
@@ -770,7 +770,7 @@ class IMAPServer(object):
         self.semaphore.release()
 
 
-class IdleThread(object):
+class IdleThread():
     def __init__(self, parent, folder=None):
         """If invoked without 'folder', perform a NOOP and wait for
         self.stop() to be called. If invoked with folder, switch to IDLE
diff --git a/offlineimap/init.py b/offlineimap/init.py
index 239dfee..be3e448 100644
--- a/offlineimap/init.py
+++ b/offlineimap/init.py
@@ -62,7 +62,7 @@ def syncitall(list_accounts, config):
     threads.wait()  # Blocks until all accounts are processed.
 
 
-class OfflineImap(object):
+class OfflineImap():
     """The main class that encapsulates the high level use of OfflineImap.
 
     To invoke OfflineImap you would call it with::
diff --git a/offlineimap/localeval.py b/offlineimap/localeval.py
index 5057a96..87a69ea 100644
--- a/offlineimap/localeval.py
+++ b/offlineimap/localeval.py
@@ -19,7 +19,7 @@
 import imp
 
 
-class LocalEval(object):
+class LocalEval():
     """Here is a powerfull but very dangerous option, of course."""
 
     def __init__(self, path=None):
diff --git a/offlineimap/mbnames.py b/offlineimap/mbnames.py
index 5374b5d..a972358 100644
--- a/offlineimap/mbnames.py
+++ b/offlineimap/mbnames.py
@@ -78,7 +78,7 @@ def writeIntermediateFile(accountname):
         _mbnames.write()
 
 
-class _IntermediateMbnames(object):
+class _IntermediateMbnames():
     """mbnames data for one account."""
 
     def __init__(self, accountname, folder_root, mbnamesdir, folderfilter,
@@ -120,7 +120,7 @@ class _IntermediateMbnames(object):
                 json.dump(itemlist, intermediateFD)
 
 
-class _Mbnames(object):
+class _Mbnames():
     def __init__(self, config, ui, dry_run):
 
         self._config = config
diff --git a/offlineimap/repository/IMAP.py b/offlineimap/repository/IMAP.py
index 5991eae..88b61d5 100644
--- a/offlineimap/repository/IMAP.py
+++ b/offlineimap/repository/IMAP.py
@@ -510,7 +510,7 @@ class IMAPRepository(BaseRepository):
                 """Converts a cmp= function into a key= function
                 We need to keep cmp functions for backward compatibility"""
 
-                class K(object):
+                class K():
                     def __init__(self, obj, *args):
                         self.obj = obj
 
diff --git a/offlineimap/repository/__init__.py b/offlineimap/repository/__init__.py
index 375b23a..12abf74 100644
--- a/offlineimap/repository/__init__.py
+++ b/offlineimap/repository/__init__.py
@@ -30,7 +30,7 @@ from offlineimap.repository.LocalStatus import LocalStatusRepository
 from offlineimap.error import OfflineImapError
 
 
-class Repository(object):
+class Repository():
     """Abstract class that returns the correct Repository type
     instance based on 'account' and 'reqtype', e.g.  a
     class:`ImapRepository` instance."""
diff --git a/offlineimap/threadutil.py b/offlineimap/threadutil.py
index 61e3545..51ae047 100644
--- a/offlineimap/threadutil.py
+++ b/offlineimap/threadutil.py
@@ -37,7 +37,7 @@ def semaphorereset(semaphore, originalstate):
         semaphore.release()
 
 
-class accountThreads(object):
+class accountThreads():
     """Store the list of all threads in the software so it can be used to find out
     what's running and what's not."""
 
diff --git a/offlineimap/ui/UIBase.py b/offlineimap/ui/UIBase.py
index f363c88..a2188f8 100644
--- a/offlineimap/ui/UIBase.py
+++ b/offlineimap/ui/UIBase.py
@@ -50,7 +50,7 @@ def getglobalui():
     return globalui
 
 
-class UIBase(object):
+class UIBase():
     def __init__(self, config, loglevel=logging.INFO):
         self.config = config
         # Is this a 'dryrun'?
diff --git a/offlineimap/utils/const.py b/offlineimap/utils/const.py
index 7dab07a..e7f86c9 100644
--- a/offlineimap/utils/const.py
+++ b/offlineimap/utils/const.py
@@ -6,7 +6,7 @@
 import copy
 
 
-class ConstProxy(object):
+class ConstProxy():
     """Implements read-only access to a given object
     that can be attached to each instance only once."""