diff --git a/src/common/connection.py b/src/common/connection.py
index 40c1d013d01eecda9c379aa34d1e92a6ca832765..49454f9aef356c7da37694acc65dcb7477824d25 100644
--- a/src/common/connection.py
+++ b/src/common/connection.py
@@ -1204,7 +1204,7 @@ class Connection(ConnectionHandlers):
 			ji = gajim.get_jid_without_resource(jid)
 			if gajim.config.should_log(self.name, ji):
 				log_msg = msg
-				if original_message != None:
+				if original_message is not None:
 					log_msg = original_message
 				if subject:
 					log_msg = _('Subject: %(subject)s\n%(message)s') % \
diff --git a/src/common/socks5.py b/src/common/socks5.py
index 773886cc5776b5f3aca0a821a8145bbe45ef85a5..9cdc33166aa5394775e9e15ce008dd7af960aa1d 100644
--- a/src/common/socks5.py
+++ b/src/common/socks5.py
@@ -893,7 +893,7 @@ class Socks5Receiver(Socks5, IdleObject):
 	
 	def connect(self):
 		''' create the socket and plug it to the idlequeue '''
-		if self.ais == None:
+		if self.ais is None:
 			return None
 
 		for ai in self.ais:
diff --git a/src/common/xmpp/browser.py b/src/common/xmpp/browser.py
index 04c562f257e9193f1b202580291d41c07ea1a8eb..8bda87874322de0708e79d5b710b51244c9c41e5 100644
--- a/src/common/xmpp/browser.py
+++ b/src/common/xmpp/browser.py
@@ -197,14 +197,14 @@ class Browser(PlugIn):
             # handler must return list: [{jid,action,node,name}]
             if type(handler)==dict: lst=handler['items']
             else: lst=handler(conn,request,'items')
-            if lst==None:
+            if lst is None:
                 conn.send(Error(request,ERR_ITEM_NOT_FOUND))
                 raise NodeProcessed
             for item in lst: q.addChild('item',item)
         elif request.getQueryNS()==NS_DISCO_INFO:
             if type(handler)==dict: dt=handler['info']
             else: dt=handler(conn,request,'info')
-            if dt==None:
+            if dt is None:
                 conn.send(Error(request,ERR_ITEM_NOT_FOUND))
                 raise NodeProcessed
             # handler must return dictionary:
diff --git a/src/common/zeroconf/connection_handlers_zeroconf.py b/src/common/zeroconf/connection_handlers_zeroconf.py
index b338ad9068baa7a4e294c5267351dec658ee85af..e6342f6cc7bd0855a209a2b9e9913c9233f7188f 100644
--- a/src/common/zeroconf/connection_handlers_zeroconf.py
+++ b/src/common/zeroconf/connection_handlers_zeroconf.py
@@ -93,7 +93,7 @@ class ConnectionBytestream(connection_handlers.ConnectionBytestream):
 					self.dispatch('ERROR', (_('Wrong host'), _('The host %s you configured as the ft_add_hosts_to_send advanced option is not valid, so ignored.') % ft_host))
 		listener = gajim.socks5queue.start_listener(port,
 			sha_str, self._result_socks5_sid, file_props['sid'])
-		if listener == None:
+		if listener is None:
 			file_props['error'] = -5
 			self.dispatch('FILE_REQUEST_ERROR', (unicode(receiver), file_props,
 				''))
@@ -263,7 +263,7 @@ class ConnectionBytestream(connection_handlers.ConnectionBytestream):
 				if proxyhost['jid'] == jid:
 					proxy = proxyhost
 
-		if proxy != None:
+		if proxy is not None:
 			file_props['streamhost-used'] = True
 			if 'streamhosts' not in file_props:
 				file_props['streamhosts'] = []
@@ -397,7 +397,7 @@ class ConnectionHandlersZeroconf(ConnectionVcard, ConnectionBytestream, connecti
 		if not mtype:
 			mtype = 'normal'
 
-		if frm == None:
+		if frm is None:
 			for key in self.connection.zeroconf.contacts:
 				if ip == self.connection.zeroconf.contacts[key][zeroconf.C_ADDRESS]:
 					frm = key
diff --git a/src/common/zeroconf/connection_zeroconf.py b/src/common/zeroconf/connection_zeroconf.py
index c21a54bdf35b9ee304b957abbc0e25394a98d9dc..283b3ab5bc5c2391edb0fb98b4ea2478a6453645 100644
--- a/src/common/zeroconf/connection_zeroconf.py
+++ b/src/common/zeroconf/connection_zeroconf.py
@@ -457,7 +457,7 @@ class ConnectionZeroconf(ConnectionHandlersZeroconf):
 			reason += ' ' + _('Your message could not be sent.')
 			self.dispatch('MSGERROR', [jid, '-1', reason, None, None, session])
 
-		ret = self.connection.send(msg_iq, msg != None, on_ok=on_send_ok,
+		ret = self.connection.send(msg_iq, msg is not None, on_ok=on_send_ok,
 			on_not_ok=on_send_not_ok)
 		if ret == -1:
 			# Contact Offline
diff --git a/src/session.py b/src/session.py
index 70a101a61b1b086235b125ae410cc4e6ac35f685..4f198ffb8ee60dfb0b7ee5686c1b179435ddc8eb 100644
--- a/src/session.py
+++ b/src/session.py
@@ -62,7 +62,7 @@ class ChatControlSession(stanza_session.EncryptedStanzaSession):
 		chatstate = None
 
 		# chatstates - look for chatstate tags in a message if not delayed
-		delayed = msg.getTag('x', namespace=common.xmpp.NS_DELAY) != None
+		delayed = msg.getTag('x', namespace=common.xmpp.NS_DELAY) is not None
 		if not delayed:
 			composing_xep = False
 			children = msg.getChildren()
diff --git a/test/lib/mock.py b/test/lib/mock.py
index 5d6348b1a19037e14e3271bd6f1789291c12b089..c4a4e63320888b3a6095fd90326a84b57a1c7bd0 100644
--- a/test/lib/mock.py
+++ b/test/lib/mock.py
@@ -116,7 +116,7 @@ class Mock:
         raise a MockInterfaceError.
         Based on the Python 2.3.3 Reference Manual section 5.3.4: Calls.
         """
-        if self.realClassMethods == None:
+        if self.realClassMethods is None:
             return
         if name not in self.realClassMethods:
             raise MockInterfaceError("Calling mock method '%s' that was not found in the original class" % name)
@@ -411,7 +411,7 @@ def NOT(cond):
 def MATCHES(regex, *args, **kwargs):
     compiled_regex = re.compile(regex, *args, **kwargs)
     def testFn(param):
-        return compiled_regex.match(param) != None
+        return compiled_regex.match(param) is not None
     return testFn
 
 def SEQ(*sequence):