diff --git a/DDSim/DD4hepSimulation.py b/DDSim/DD4hepSimulation.py
index 929266ff315dbafe86c3f4a35f484e85854737b3..3779f0566208797e80d8d47bcaee78ede03ba444 100644
--- a/DDSim/DD4hepSimulation.py
+++ b/DDSim/DD4hepSimulation.py
@@ -611,6 +611,7 @@ class DD4hepSimulation(object):
       for pattern in self.action.mapActions:
         if pattern.lower() in det.lower():
           action = self.action.mapActions[pattern]
+          print  '       replace default action with : ' , action 
           break
       seq,act = setupFuction( det, type=action )
       self.filter.applyFilters( seq, det, defaultFilter )