diff --git a/Simulation/DetSimSD/DetSimSD/CaloSensitiveDetector.h b/Simulation/DetSimSD/DetSimSD/CaloSensitiveDetector.h
index f9cbda02c03823ddf02d05d4642eab4d015e4f2c..28b3ab3b11f7e48b6f300402e1e9e9edefd986bb 100644
--- a/Simulation/DetSimSD/DetSimSD/CaloSensitiveDetector.h
+++ b/Simulation/DetSimSD/DetSimSD/CaloSensitiveDetector.h
@@ -12,7 +12,7 @@
 class CaloSensitiveDetector: public DDG4SensitiveDetector {
 public:
     typedef dd4hep::sim::Geant4CalorimeterHit CalorimeterHit;
-    typedef G4THitsCollection<CalorimeterHit> HitCollection;
+    typedef G4THitsCollection<CalorimeterHit> CaloHitCollection;
 
 public:
     CaloSensitiveDetector(const std::string& name, dd4hep::Detector& description);
diff --git a/Simulation/DetSimSD/DetSimSD/DDG4SensitiveDetector.h b/Simulation/DetSimSD/DetSimSD/DDG4SensitiveDetector.h
index 94d9525b3f76ff596094911f39b80ec5518e11d3..f7806f7de5f97c5cf36a60c6b22e6d1491ccb24e 100644
--- a/Simulation/DetSimSD/DetSimSD/DDG4SensitiveDetector.h
+++ b/Simulation/DetSimSD/DetSimSD/DDG4SensitiveDetector.h
@@ -26,6 +26,7 @@
 
 class DDG4SensitiveDetector: public G4VSensitiveDetector {
 public:
+    typedef dd4hep::sim::Geant4Hit                    Geant4Hit;
     typedef G4THitsCollection<dd4hep::sim::Geant4Hit> HitCollection;
     typedef dd4hep::sim::Geant4Hit::Contribution      HitContribution;
 
diff --git a/Simulation/DetSimSD/src/CaloSensitiveDetector.cpp b/Simulation/DetSimSD/src/CaloSensitiveDetector.cpp
index ba740941060329531d4588b2c0f72c6523839d88..1547f9fe3506be659803ef0d8f5da2e3bcd79fdf 100644
--- a/Simulation/DetSimSD/src/CaloSensitiveDetector.cpp
+++ b/Simulation/DetSimSD/src/CaloSensitiveDetector.cpp
@@ -16,7 +16,8 @@ CaloSensitiveDetector::Initialize(G4HCofThisEvent* HCE) {
 
     // the collection name is provided by DD4hep
     const std::string& coll_name = collectionName[0];
-    m_hc = new G4THitsCollection<CalorimeterHit>(GetName(), coll_name);
+    // m_hc = new G4THitsCollection<CalorimeterHit>(GetName(), coll_name);
+    m_hc = new HitCollection(GetName(), coll_name);
 
     int HCID = -1;
     if(HCID<0) HCID = G4SDManager::GetSDMpointer()->GetCollectionID(m_hc);