diff --git a/src/bitmessageqt/__init__.py b/src/bitmessageqt/__init__.py
index 40113b5a..b4ce8678 100644
--- a/src/bitmessageqt/__init__.py
+++ b/src/bitmessageqt/__init__.py
@@ -14,6 +14,7 @@ import threading
 import time
 from datetime import datetime, timedelta
 from sqlite3 import register_adapter
+import six
 
 from PyQt4 import QtCore, QtGui
 from PyQt4.QtNetwork import QLocalSocket, QLocalServer
@@ -468,7 +469,7 @@ class MyForm(settingsmixin.SMainWindow):
             # add missing folders
             if len(db[toAddress]) > 0:
                 j = 0
-                for f, c in db[toAddress].iteritems():
+                for f, c in six.iteritems(db[toAddress]):
                     try:
                         subwidget = Ui_FolderWidget(widget, j, toAddress, f, c['count'])
                     except KeyError:
@@ -598,7 +599,7 @@ class MyForm(settingsmixin.SMainWindow):
             # add missing folders
             if len(db[toAddress]) > 0:
                 j = 0
-                for f, c in db[toAddress].iteritems():
+                for f, c in six.iteritems(db[toAddress]):
                     if toAddress is not None and tab == 'messages' and folder == "new":
                         continue
                     subwidget = Ui_FolderWidget(widget, j, toAddress, f, c)
@@ -1075,15 +1076,15 @@ class MyForm(settingsmixin.SMainWindow):
             for i in range(root.childCount()):
                 addressItem = root.child(i)
                 if addressItem.type == AccountMixin.ALL:
-                    newCount = sum(totalUnread.itervalues())
+                    newCount = sum(six.itervalues(totalUnread))
                     self.drawTrayIcon(self.currentTrayIconFileName, newCount)
                 else:
                     try:
-                        newCount = sum((
+                        newCount = sum(six.itervalues((
                             broadcastsUnread
                             if addressItem.type == AccountMixin.SUBSCRIPTION
                             else normalUnread
-                        )[addressItem.address].itervalues())
+                        )[addressItem.address]))
                     except KeyError:
                         newCount = 0
                 if newCount != addressItem.unreadCount:
@@ -2871,7 +2872,7 @@ class MyForm(settingsmixin.SMainWindow):
             QtCore.QEventLoop.AllEvents, 1000
         )
         self.saveSettings()
-        for attr, obj in self.ui.__dict__.iteritems():
+        for attr, obj in six.iteritems(self.ui.__dict__):
             if hasattr(obj, "__class__") \
                     and isinstance(obj, settingsmixin.SettingsMixin):
                 saveMethod = getattr(obj, "saveSettings", None)
@@ -4209,7 +4210,7 @@ class MyForm(settingsmixin.SMainWindow):
 
     def initSettings(self):
         self.loadSettings()
-        for attr, obj in self.ui.__dict__.iteritems():
+        for attr, obj in six.iteritems(self.ui.__dict__):
             if hasattr(obj, "__class__") and \
                     isinstance(obj, settingsmixin.SettingsMixin):
                 loadMethod = getattr(obj, "loadSettings", None)
diff --git a/src/bitmessageqt/retranslateui.py b/src/bitmessageqt/retranslateui.py
index c7676f77..1b4b7716 100644
--- a/src/bitmessageqt/retranslateui.py
+++ b/src/bitmessageqt/retranslateui.py
@@ -1,4 +1,5 @@
 from os import path
+import six
 from PyQt4 import QtGui
 from debug import logger
 import widgets
@@ -7,7 +8,7 @@ class RetranslateMixin(object):
     def retranslateUi(self):
         defaults = QtGui.QWidget()
         widgets.load(self.__class__.__name__.lower() + '.ui', defaults)
-        for attr, value in defaults.__dict__.iteritems():
+        for attr, value in six.iteritems(defaults.__dict__):
             setTextMethod = getattr(value, "setText", None)
             if callable(setTextMethod):
                 getattr(self, attr).setText(getattr(defaults, attr).text())
diff --git a/src/network/dandelion.py b/src/network/dandelion.py
index 35e70c95..e2232082 100644
--- a/src/network/dandelion.py
+++ b/src/network/dandelion.py
@@ -6,6 +6,7 @@ from collections import namedtuple
 from random import choice, expovariate, sample
 from threading import RLock
 from time import time
+import six
 
 import connectionpool
 import state
@@ -99,12 +100,12 @@ class Dandelion:  # pylint: disable=old-style-class
         with self.lock:
             if len(self.stem) < MAX_STEMS:
                 self.stem.append(connection)
-                for k in (k for k, v in self.nodeMap.iteritems() if v is None):
+                for k in (k for k, v in six.iteritems(self.nodeMap) if v is None):
                     self.nodeMap[k] = connection
-                for k, v in {
-                        k: v for k, v in self.hashMap.iteritems()
+                for k, v in six.iteritems({
+                        k: v for k, v in six.iteritems(self.hashMap)
                         if v.child is None
-                }.iteritems():
+                }):
                     self.hashMap[k] = Stem(
                         connection, v.stream, self.poissonTimeout())
                     invQueue.put((v.stream, k, v.child))
@@ -120,14 +121,14 @@ class Dandelion:  # pylint: disable=old-style-class
                 self.stem.remove(connection)
                 # active mappings to pointing to the removed node
                 for k in (
-                        k for k, v in self.nodeMap.iteritems()
+                        k for k, v in six.iteritems(self.nodeMap)
                         if v == connection
                 ):
                     self.nodeMap[k] = None
-                for k, v in {
-                        k: v for k, v in self.hashMap.iteritems()
+                for k, v in six.iteritems({
+                        k: v for k, v in six.iteritems(self.hashMap)
                         if v.child == connection
-                }.iteritems():
+                }):
                     self.hashMap[k] = Stem(
                         None, v.stream, self.poissonTimeout())
 
@@ -168,7 +169,7 @@ class Dandelion:  # pylint: disable=old-style-class
         with self.lock:
             deadline = time()
             toDelete = [
-                [v.stream, k, v.child] for k, v in self.hashMap.iteritems()
+                [v.stream, k, v.child] for k, v in six.iteritems(self.hashMap)
                 if v.timeout < deadline
             ]
 
diff --git a/src/network/downloadthread.py b/src/network/downloadthread.py
index 4f108c72..15013a3b 100644
--- a/src/network/downloadthread.py
+++ b/src/network/downloadthread.py
@@ -3,6 +3,7 @@
 """
 import time
 import state
+import six
 import addresses
 import helper_random
 import protocol
@@ -28,7 +29,7 @@ class DownloadThread(StoppableThread):
         deadline = time.time() - self.requestExpires
         try:
             toDelete = [
-                k for k, v in missingObjects.iteritems()
+                k for k, v in six.iteritems(missingObjects)
                 if v < deadline]
         except RuntimeError:
             pass
diff --git a/src/network/knownnodes.py b/src/network/knownnodes.py
index c53be2cd..f0fd6d90 100644
--- a/src/network/knownnodes.py
+++ b/src/network/knownnodes.py
@@ -14,6 +14,7 @@ try:
     from collections.abc import Iterable
 except ImportError:
     from collections import Iterable
+import six
 
 import state
 from bmconfigparser import config
@@ -54,8 +55,8 @@ def json_serialize_knownnodes(output):
     Reorganize knownnodes dict and write it as JSON to output
     """
     _serialized = []
-    for stream, peers in knownNodes.iteritems():
-        for peer, info in peers.iteritems():
+    for stream, peers in six.iteritems(knownNodes):
+        for peer, info in six.iteritems(peers):
             info.update(rating=round(info.get('rating', 0), 2))
             _serialized.append({
                 'stream': stream, 'peer': peer._asdict(), 'info': info
@@ -87,7 +88,7 @@ def pickle_deserialize_old_knownnodes(source):
     global knownNodes
     knownNodes = pickle.load(source)  # nosec B301
     for stream in knownNodes.keys():
-        for node, params in knownNodes[stream].iteritems():
+        for node, params in six.iteritems(knownNodes[stream]):
             if isinstance(params, (float, int)):
                 addKnownNode(stream, node, params)
 
diff --git a/src/network/objectracker.py b/src/network/objectracker.py
index a458e5d2..f1cfa131 100644
--- a/src/network/objectracker.py
+++ b/src/network/objectracker.py
@@ -3,6 +3,7 @@ Module for tracking objects
 """
 import time
 from threading import RLock
+import six
 
 import state
 import connectionpool
@@ -75,7 +76,7 @@ class ObjectTracker(object):
                 with self.objectsNewToThemLock:
                     self.objectsNewToThem = {
                         k: v
-                        for k, v in self.objectsNewToThem.iteritems()
+                        for k, v in six.iteritems(self.objectsNewToThem)
                         if v >= deadline}
             self.lastCleaned = time.time()
 
diff --git a/src/network/tcp.py b/src/network/tcp.py
index 139715a6..a31544fd 100644
--- a/src/network/tcp.py
+++ b/src/network/tcp.py
@@ -8,6 +8,7 @@ import math
 import random
 import socket
 import time
+import six
 
 # magic imports!
 import addresses
@@ -191,7 +192,7 @@ class TCPConnection(BMProto, TLSDispatcher):
                     # only if more recent than 3 hours
                     # and having positive or neutral rating
                     filtered = [
-                        (k, v) for k, v in nodes.iteritems()
+                        (k, v) for k, v in six.iteritems(nodes)
                         if v["lastseen"] > int(time.time())
                         - maximumAgeOfNodesThatIAdvertiseToOthers
                         and v["rating"] >= 0 and not k.host.endswith('.onion')
diff --git a/src/tests/core.py b/src/tests/core.py
index f1a11a06..e24293b0 100644
--- a/src/tests/core.py
+++ b/src/tests/core.py
@@ -15,6 +15,7 @@ import sys
 import threading
 import time
 import unittest
+import six
 
 import protocol
 import state
@@ -137,8 +138,8 @@ class TestCore(unittest.TestCase):
     @staticmethod
     def _outdate_knownnodes():
         with knownnodes.knownNodesLock:
-            for nodes in knownnodes.knownNodes.itervalues():
-                for node in nodes.itervalues():
+            for nodes in six.itervalues(knownnodes.knownNodes):
+                for node in six.itervalues(nodes):
                     node['lastseen'] -= 2419205  # older than 28 days
 
     def test_knownnodes_pickle(self):
@@ -146,9 +147,9 @@ class TestCore(unittest.TestCase):
         pickle_knownnodes()
         self._wipe_knownnodes()
         knownnodes.readKnownNodes()
-        for nodes in knownnodes.knownNodes.itervalues():
+        for nodes in six.itervalues(knownnodes.knownNodes):
             self_count = n = 0
-            for n, node in enumerate(nodes.itervalues()):
+            for n, node in enumerate(six.itervalues(nodes)):
                 if node.get('self'):
                     self_count += 1
             self.assertEqual(n - self_count, 2)
@@ -202,7 +203,7 @@ class TestCore(unittest.TestCase):
         while c > 0:
             time.sleep(1)
             c -= 2
-            for peer, con in connectionpool.pool.outboundConnections.iteritems():
+            for peer, con in six.iteritems(connectionpool.pool.outboundConnections):
                 if (
                     peer.host.startswith('bootstrap')
                     or peer.host == 'quzwelsuziwqgpt2.onion'
@@ -223,7 +224,7 @@ class TestCore(unittest.TestCase):
             'Failed to connect during %.2f sec' % (time.time() - _started))
 
     def _check_knownnodes(self):
-        for stream in knownnodes.knownNodes.itervalues():
+        for stream in six.itervalues(knownnodes.knownNodes):
             for peer in stream:
                 if peer.host.startswith('bootstrap'):
                     self.fail(