diff --git a/Simulation/Digitization/python/DigitizationParametersConfig.py b/Simulation/Digitization/python/DigitizationParametersConfig.py
index 1750134ad465f0c3bc84740624640dc7085d12b5..87f1fc7848f82c7dd1a44dd9e4050abce941e975 100644
--- a/Simulation/Digitization/python/DigitizationParametersConfig.py
+++ b/Simulation/Digitization/python/DigitizationParametersConfig.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 
 from AthenaCommon.Logging import logging
 logDigitizationWriteMetadata = logging.getLogger( 'DigitizationParametersConfig' )
@@ -39,7 +39,7 @@ def writeDigitizationMetadata(ConfigFlags):
                           'DetDescrVersion' : 'GeoModel.AtlasVersion'
                       }
     logDigitizationWriteMetadata.info('Filling Digitization MetaData')
-    for testKey, testFlag in digitMetaDataKeys.iteritems():
+    for testKey, testFlag in digitMetaDataKeys.items():
         if ConfigFlags.hasFlag(testFlag):
             testValue = ConfigFlags._get(testFlag)
             if not isinstance(testValue, str):
diff --git a/Simulation/G4Atlas/G4AtlasApps/share/jobOptions.G4Atlas.py b/Simulation/G4Atlas/G4AtlasApps/share/jobOptions.G4Atlas.py
index 39b292a2a46167304427d8b2e63de187366e4c7f..ad90fb5964ad389fda6a5aead98ed6041c095cf3 100644
--- a/Simulation/G4Atlas/G4AtlasApps/share/jobOptions.G4Atlas.py
+++ b/Simulation/G4Atlas/G4AtlasApps/share/jobOptions.G4Atlas.py
@@ -1,4 +1,7 @@
+# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+
 ## Job options file for Geant4 ATLAS detector simulations
+from __future__ import print_function
 
 ## Algorithm sequence
 from AthenaCommon.AlgSequence import AlgSequence
@@ -74,7 +77,7 @@ pg = PG.ParticleGun(randomSvcName=simFlags.RandomSvc.get_Value(), randomStream="
 pg.sampler.pid = 999 #Geantino
 pg.sampler.mom = PG.EEtaMPhiSampler(energy=50000, eta=[-3,3])
 topSeq += pg
-print topSeq.ParticleGun
+print (topSeq.ParticleGun)
 
 # This should only be used when evgen is run in the simulation step
 include('G4AtlasApps/fragment.SimCopyWeights.py')
@@ -90,4 +93,4 @@ topSeq += getAlgorithm("BeamEffectsAlg", tryDefaultConfigurable=True)
 ## Add the G4 sim to the alg sequence after the generator
 from AthenaCommon.CfgGetter import getAlgorithm
 topSeq += getAlgorithm("G4AtlasAlg",tryDefaultConfigurable=True)
-print topSeq
+print (topSeq)
diff --git a/Simulation/G4Utilities/G4DebuggingTools/python/G4DebuggingToolsConfig.py b/Simulation/G4Utilities/G4DebuggingTools/python/G4DebuggingToolsConfig.py
index e884a92cb8349fad76c7a5350c7f271584ecb9a5..ba14dbdcb07eaeec6208f99c73eeff1e49ee91fe 100644
--- a/Simulation/G4Utilities/G4DebuggingTools/python/G4DebuggingToolsConfig.py
+++ b/Simulation/G4Utilities/G4DebuggingTools/python/G4DebuggingToolsConfig.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 
 from AthenaCommon import CfgMgr, Logging
 from G4AtlasServices import G4AtlasServicesConfig
@@ -7,7 +7,7 @@ def getVerboseSelectorTool(name="G4UA::VerboseSelectorTool", **kwargs):
     from G4AtlasApps.SimFlags import simFlags
     # example custom configuration
     if name in simFlags.UserActionConfig.get_Value().keys():
-        for prop,value in simFlags.UserActionConfig.get_Value()[name].iteritems():
+        for prop,value in simFlags.UserActionConfig.get_Value()[name].items():
             kwargs.setdefault(prop,value)
     return CfgMgr.G4UA__VerboseSelectorTool(name, **kwargs)
 
@@ -21,7 +21,7 @@ def getHyperspaceCatcherTool(name="G4UA::HyperspaceCatcherTool", **kwargs):
     from G4AtlasApps.SimFlags import simFlags
     # example custom configuration
     if name in simFlags.UserActionConfig.get_Value().keys():
-        for prop,value in simFlags.UserActionConfig.get_Value()[name].iteritems():
+        for prop,value in simFlags.UserActionConfig.get_Value()[name].items():
             kwargs.setdefault(prop,value)
     return CfgMgr.G4UA__HyperspaceCatcherTool(name, **kwargs)
 
@@ -41,7 +41,7 @@ def getVolumeDebuggerTool(name="G4UA::VolumeDebuggerTool", **kwargs):
     from G4AtlasApps.SimFlags import simFlags
     # example custom configuration
     if name in simFlags.UserActionConfig.get_Value().keys():
-        for prop,value in simFlags.UserActionConfig.get_Value()[name].iteritems():
+        for prop,value in simFlags.UserActionConfig.get_Value()[name].items():
             kwargs.setdefault(prop,value)
     return CfgMgr.G4UA__VolumeDebuggerTool(name, **kwargs)
 
@@ -56,7 +56,7 @@ def getGeant4SetupCheckerTool(name="G4UA::Geant4SetupCheckerTool", **kwargs):
     kwargs.setdefault('ReferenceFile',default_file)
     # Grab the properties that were already set
     if name in simFlags.UserActionConfig.get_Value().keys():
-        for prop,value in simFlags.UserActionConfig.get_Value()[name].iteritems():
+        for prop,value in simFlags.UserActionConfig.get_Value()[name].items():
             kwargs.setdefault(prop,value)
     # Set up the user action
     return CfgMgr.G4UA__Geant4SetupCheckerTool(name, **kwargs)
@@ -69,7 +69,7 @@ def getStepHistogramTool(name="G4UA::StepHistogramTool", **kwargs):
         return False
     from G4AtlasApps.SimFlags import simFlags
     if name in simFlags.UserActionConfig.get_Value().keys():
-        for prop,value in simFlags.UserActionConfig.get_Value()[name].iteritems():
+        for prop,value in simFlags.UserActionConfig.get_Value()[name].items():
             kwargs.setdefault(prop,value)
     return CfgMgr.G4UA__StepHistogramTool(name, **kwargs)