diff --git a/DDSim/DD4hepSimulation.py b/DDSim/DD4hepSimulation.py
index e35a5881b4cf11a148c05972b77fc9fa240630aa..13289090f06db7a8e7c90a743fb9c6c0dfedb63c 100644
--- a/DDSim/DD4hepSimulation.py
+++ b/DDSim/DD4hepSimulation.py
@@ -86,6 +86,7 @@ class DD4hepSimulation(object):
 
     self.filter = Filter()
     self.physics = Physics()
+    self.readerParameters = {}
 
     ### use TCSH geant UI instead of QT
     os.environ['G4UI_USE_TCSH'] = "1"
@@ -347,24 +348,32 @@ class DD4hepSimulation(object):
       actionList.append(self._g4gps)
 
     for index,inputFile in enumerate(self.inputFiles, start=4):
+      print " ******** self.readerParameters = ", self.readerParameters
       if inputFile.endswith(".slcio"):
         gen = DDG4.GeneratorAction(kernel,"LCIOInputAction/LCIO%d" % index)
         gen.Input="LCIOFileReader|"+inputFile
+        gen.Parameters = self.readerParameters
       elif inputFile.endswith(".stdhep"):
         gen = DDG4.GeneratorAction(kernel,"LCIOInputAction/STDHEP%d" % index)
         gen.Input="LCIOStdHepReader|"+inputFile
+        gen.Parameters = self.readerParameters
       elif inputFile.endswith(".HEPEvt"):
         gen = DDG4.GeneratorAction(kernel,"Geant4InputAction/HEPEvt%d" % index)
         gen.Input="Geant4EventReaderHepEvtShort|"+inputFile
+        gen.Parameters = self.readerParameters
       elif inputFile.endswith(".hepevt"):
         gen = DDG4.GeneratorAction(kernel,"Geant4InputAction/hepevt%d" % index)
         gen.Input="Geant4EventReaderHepEvtLong|"+inputFile
+        gen.Parameters = self.readerParameters
       elif inputFile.endswith(".hepmc"):
         gen = DDG4.GeneratorAction(kernel,"Geant4InputAction/hepmc%d" % index)
         gen.Input="Geant4EventReaderHepMC|"+inputFile
+        gen.Parameters = self.readerParameters
       elif inputFile.endswith(".pairs"):
         gen = DDG4.GeneratorAction(kernel,"Geant4InputAction/HEPEvt%d" % index)
         gen.Input="Geant4EventReaderGuineaPig|"+inputFile
+        gen.Parameters = self.readerParameters
+
       else:
         ##this should never happen because we already check at the top, but in case of some LogicError...
         raise RuntimeError( "Unknown input file type: %s" % inputFile )