diff --git a/DDCore/python/lcdd.py b/DDCore/python/lcdd.py
index 625249d7a0bf2a81e1c8eb53e5ff33a81a5b2194..915c6db4557374b67a0b2f5bbcebb0ba3c29600b 100644
--- a/DDCore/python/lcdd.py
+++ b/DDCore/python/lcdd.py
@@ -18,6 +18,7 @@ import SystemOfUnits
 import math
 import logging
 from six.moves import range
+from io import open
 from ROOT import SetOwnership, dd4hep, TGeoMixture, TGeoMedium, gGeoManager, TNamed
 
 logging.basicConfig(format='%(levelname)s: %(message)s')
diff --git a/DDG4/python/DDSim/DD4hepSimulation.py b/DDG4/python/DDSim/DD4hepSimulation.py
index d3141dcf089740aff708d186208de87dcdb8c0cb..f9e15e3db4328cb88088395109ae1891a4231395 100644
--- a/DDG4/python/DDSim/DD4hepSimulation.py
+++ b/DDG4/python/DDSim/DD4hepSimulation.py
@@ -7,10 +7,11 @@ Based on M. Frank and F. Gaede runSim.py
 
 """
 from __future__ import absolute_import, unicode_literals, division
-import six
 __RCSID__ = "$Id$"
+import six
 from g4units import *
 import logging
+from io import open
 
 logging.basicConfig(format='%(levelname)s: %(message)s')
 logger = logging.getLogger(__name__)