diff --git a/CLDConfig/cld_steer.py b/CLDConfig/cld_steer.py
index 2167a1b..afb97eb 100644
--- a/CLDConfig/cld_steer.py
+++ b/CLDConfig/cld_steer.py
@@ -199,6 +199,8 @@
 ## Configuration for the Particle Handler/ MCTruth treatment
 ################################################################################
 
+SIM.part.userParticleHandler = "Geant4TVUserParticleHandler"
+
 ##  Keep all created particles
 SIM.part.keepAllParticles = False