diff --git a/include/FastCaloSim/Core/TFCSBinnedShowerBase.h b/include/FastCaloSim/Core/TFCSBinnedShowerBase.h
index bfc333c..92a0374 100644
--- a/include/FastCaloSim/Core/TFCSBinnedShowerBase.h
+++ b/include/FastCaloSim/Core/TFCSBinnedShowerBase.h
@@ -115,6 +115,15 @@ class TFCSBinnedShowerBase : public TFCSLateralShapeParametrizationHitBase
   // Delete all pointers that were created in get_event()
   virtual void delete_event(TFCSSimulationState& simulstate) const = 0;
 
+  // Called by TFCSSimulationState::DoAuxInfoCleanup() to free heap-allocated
+  // aux-info objects. Invoked automatically on simulstate destruction so that
+  // the BSEventData/BSNHits/BSELayer pointers are never leaked even when no
+  // subsequent simulate() call cleans them up first.
+  virtual void CleanAuxInfo(TFCSSimulationState& simulstate) const override
+  {
+    delete_event(simulstate);
+  }
+
   // What should be the average energy per hit in the library
   float m_default_hit_energy = 4.;
   // What is the maximum number of hits per voxel (for runtime reasons)
diff --git a/include/FastCaloSim/Core/TFCSSimulationState.h b/include/FastCaloSim/Core/TFCSSimulationState.h
index f7fab99..88451a6 100644
--- a/include/FastCaloSim/Core/TFCSSimulationState.h
+++ b/include/FastCaloSim/Core/TFCSSimulationState.h
@@ -26,6 +26,7 @@ class FASTCALOSIM_EXPORT TFCSSimulationState
 {
 public:
   TFCSSimulationState(CLHEP::HepRandomEngine* randomEngine = nullptr);
+  virtual ~TFCSSimulationState();
 
   CLHEP::HepRandomEngine* randomEngine() { return m_randomEngine; }
   void setRandomEngine(CLHEP::HepRandomEngine* engine)
diff --git a/source/Core/TFCSBinnedShowerBase.cxx b/source/Core/TFCSBinnedShowerBase.cxx
index dfc6bae..2caa600 100644
--- a/source/Core/TFCSBinnedShowerBase.cxx
+++ b/source/Core/TFCSBinnedShowerBase.cxx
@@ -67,6 +67,12 @@ FCSReturnCode TFCSBinnedShowerBase::simulate(
   // Reset the total energy
   simulstate.set_E(0);
 
+  // Register this object as a cleanup handler so that DoAuxInfoCleanup()
+  // (called from ~TFCSSimulationState) will invoke CleanAuxInfo() ->
+  // delete_event() even if no subsequent simulate() call runs first.
+  // AddAuxInfoCleanup uses a set, so repeated calls are idempotent.
+  simulstate.AddAuxInfoCleanup(this);
+
   get_event(simulstate, eta_center, phi_center, Einit, reference_layer_index);
 
   for (long unsigned int layer_index = 0; layer_index < m_geo->n_layers();
diff --git a/source/Core/TFCSSimulationState.cxx b/source/Core/TFCSSimulationState.cxx
index c19be03..c73208f 100644
--- a/source/Core/TFCSSimulationState.cxx
+++ b/source/Core/TFCSSimulationState.cxx
@@ -21,10 +21,15 @@ TFCSSimulationState::TFCSSimulationState(CLHEP::HepRandomEngine* randomEngine)
   clear();
 }
 
+TFCSSimulationState::~TFCSSimulationState()
+{
+  DoAuxInfoCleanup();
+}
+
 void TFCSSimulationState::clear()
 {
   set_SF(1);
-  m_Ebin = -1;
+
   m_Etot = 0;
   m_E.clear();
   m_Efrac.clear();