diff -rupN qgis-2.18.20/python/PyQt/PyQt4/QtCore.py qgis-2.18.20-new/python/PyQt/PyQt4/QtCore.py
--- qgis-2.18.20/python/PyQt/PyQt4/QtCore.py	2018-05-18 14:01:08.000000000 +0200
+++ qgis-2.18.20-new/python/PyQt/PyQt4/QtCore.py	2018-11-01 22:07:20.597278848 +0100
@@ -23,7 +23,7 @@ __copyright__ = '(C) 2015, Matthias Kuhn
 # This will get replaced with a git SHA1 when you do a git archive
 __revision__ = '$Format:%H$'
 
-import sip
+import PyQt4.sip as sip
 for api in ["QDate", "QDateTime", "QString", "QTextStream", "QTime", "QUrl", "QVariant"]:
     sip.setapi(api, 2)
 
diff -rupN qgis-2.18.20/python/PyQt/PyQt4/uic/pyuic.py qgis-2.18.20-new/python/PyQt/PyQt4/uic/pyuic.py
--- qgis-2.18.20/python/PyQt/PyQt4/uic/pyuic.py	2018-05-18 14:01:08.000000000 +0200
+++ qgis-2.18.20-new/python/PyQt/PyQt4/uic/pyuic.py	2018-11-01 22:07:15.417251277 +0100
@@ -24,7 +24,7 @@ __copyright__ = '(C) 2016, Jürgen E. Fi
 __revision__ = '$Format:%H$'
 
 
-import sip
+import PyQt4.sip as sip
 for api in ["QDate", "QDateTime", "QString", "QTextStream", "QTime", "QUrl", "QVariant"]:
     sip.setapi(api, 2)
 
diff -rupN qgis-2.18.20/src/python/qgspythonutilsimpl.cpp qgis-2.18.20-new/src/python/qgspythonutilsimpl.cpp
--- qgis-2.18.20/src/python/qgspythonutilsimpl.cpp	2018-05-18 14:01:08.000000000 +0200
+++ qgis-2.18.20-new/src/python/qgspythonutilsimpl.cpp	2018-11-01 22:07:08.002211865 +0100
@@ -122,7 +122,7 @@ bool QgsPythonUtilsImpl::checkSystemImpo
   runString( "sys.path = [" + newpaths.join( "," ) + "] + sys.path" );
 
   // import SIP
-  if ( !runString( "import sip",
+  if ( !runString( "import PyQt4.sip as sip",
                    QObject::tr( "Couldn't load SIP module." ) + '\n' + QObject::tr( "Python support will be disabled." ) ) )
   {
     return false;
diff -rupN qgis-2.18.20/tests/src/python/test_qgsmaplayerregistry.py qgis-2.18.20-new/tests/src/python/test_qgsmaplayerregistry.py
--- qgis-2.18.20/tests/src/python/test_qgsmaplayerregistry.py	2018-05-18 14:01:08.000000000 +0200
+++ qgis-2.18.20-new/tests/src/python/test_qgsmaplayerregistry.py	2018-11-01 22:06:59.632167456 +0100
@@ -15,7 +15,7 @@ __revision__ = '$Format:%H$'
 from qgis.core import QgsMapLayerRegistry, QgsVectorLayer, QgsMapLayer
 from qgis.testing import start_app, unittest
 from qgis.PyQt.QtCore import QT_VERSION_STR
-import sip
+import PyQt4.sip as sip
 
 try:
     from qgis.PyQt.QtTest import QSignalSpy