diff --git a/DCHdigi/dataFormatExtension/driftChamberHit.yaml b/DCHdigi/dataFormatExtension/driftChamberHit.yaml
index fd42930..228668e 100644
--- a/DCHdigi/dataFormatExtension/driftChamberHit.yaml
+++ b/DCHdigi/dataFormatExtension/driftChamberHit.yaml
@@ -43,7 +43,7 @@ datatypes:
       - extension::DriftChamberDigi digi    // reference to the digitized hit
       - edm4hep::SimTrackerHit sim // reference to the simulated hit
 
-  edm4hep::DriftChamberDigiV2:
+  extension::DriftChamberDigiV2:
     Description: "Digitized hit (before tracking) for Drift Chamber v2 (requires data extension)."
     Author: "A. Tolosa-Delgado, B. Francois, CERN"
     Members:
@@ -59,28 +59,11 @@ datatypes:
       - uint32_t clusterCount         // number of clusters associated to this hit
       - uint32_t clusterSize          // number of electrons per cluster
 
-  edm4hep::MCRecoDriftChamberDigiV2Association:
+  extension::MCRecoDriftChamberDigiV2Association:
     Description: "Association between a DriftChamberDigi and the corresponding simulated hit"
     Author: "B. Francois, CERN"
     Members:
       - float weight              // weight of this association
     OneToOneRelations:
-      - edm4hep::DriftChamberDigiV2 digi    // reference to the digitized hit
+      - extension::DriftChamberDigiV2 digi    // reference to the digitized hit
       - edm4hep::SimTrackerHit sim // reference to the simulated hit
-
-interfaces:
-  edm4hep::TrackerHit:
-    Description: "Evolution of tracker hit interface class"
-    Author: "Thomas Madlener, DESY"
-    Members:
-      - uint64_t cellID // ID of the sensor that created this hit
-      - int32_t type // type of the raw data hit
-      - int32_t quality // quality bit flag of the hit
-      - float time [ns] // time of the hit
-      - float eDep [GeV] // energy deposited on the hit
-      - float eDepError [GeV] // error measured on eDep
-      - edm4hep::Vector3d position [mm] // hit position
-    Types:
-      - edm4hep::TrackerHit3D
-      - edm4hep::TrackerHitPlane
-      - edm4hep::DriftChamberDigiV2
diff --git a/DCHdigi/include/DCHdigi.h b/DCHdigi/include/DCHdigi.h
index a9cf72d..08659a4 100644
--- a/DCHdigi/include/DCHdigi.h
+++ b/DCHdigi/include/DCHdigi.h
@@ -12,7 +12,7 @@
  * Processor produces collection of Digitized hits of Drift Chamber v2<br>
  * @param DCH_simhits The name of input collection, type edm4hep::SimTrackerHitCollection <br>
  * (default name empty) <br>
- * @param DCH_DigiCollection The name of out collection, type edm4hep::DriftChamberDigiV2Collection <br>
+ * @param DCH_DigiCollection The name of out collection, type extension::DriftChamberDigiV2Collection <br>
  * (default name DCH_DigiCollection) <br>
  * @param DCH_name DCH subdetector name <br>
  * (default value DCH_v2) <br>
@@ -78,14 +78,14 @@ constexpr double MM_TO_CM = 0.1;
 
 struct DCHdigi final
     : k4FWCore::MultiTransformer<
-          std::tuple<edm4hep::DriftChamberDigiV2Collection,edm4hep::MCRecoDriftChamberDigiV2AssociationCollection>(
+          std::tuple<extension::DriftChamberDigiV2Collection,extension::MCRecoDriftChamberDigiV2AssociationCollection>(
               const edm4hep::SimTrackerHitCollection&, const edm4hep::EventHeaderCollection&)> {
   DCHdigi(const std::string& name, ISvcLocator* svcLoc);
 
   StatusCode initialize() override;
   StatusCode finalize() override;
 
-  std::tuple<edm4hep::DriftChamberDigiV2Collection,edm4hep::MCRecoDriftChamberDigiV2AssociationCollection> operator()(
+  std::tuple<extension::DriftChamberDigiV2Collection,extension::MCRecoDriftChamberDigiV2AssociationCollection> operator()(
       const edm4hep::SimTrackerHitCollection& ,
       const edm4hep::EventHeaderCollection&   ) const override;
 
diff --git a/DCHdigi/src/DCHdigi.cpp b/DCHdigi/src/DCHdigi.cpp
index 1880ad4..5e00be4 100644
--- a/DCHdigi/src/DCHdigi.cpp
+++ b/DCHdigi/src/DCHdigi.cpp
@@ -97,7 +97,7 @@ StatusCode DCHdigi::initialize() {
 ///////////////////////////////////////////////////////////////////////////////////////
 ///////////////////////       operator()       ////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////////////
-std::tuple<edm4hep::DriftChamberDigiV2Collection,edm4hep::MCRecoDriftChamberDigiV2AssociationCollection>
+std::tuple<extension::DriftChamberDigiV2Collection,extension::MCRecoDriftChamberDigiV2AssociationCollection>
 DCHdigi::operator()(const edm4hep::SimTrackerHitCollection& input_sim_hits,
     const edm4hep::EventHeaderCollection&  headers) const {
 
@@ -107,8 +107,8 @@ DCHdigi::operator()(const edm4hep::SimTrackerHitCollection& input_sim_hits,
     debug() << "Input Sim Hit collection size: " << input_sim_hits.size() << endmsg;
 
     // Create the collections we are going to return
-    edm4hep::DriftChamberDigiV2Collection output_digi_hits;
-    edm4hep::MCRecoDriftChamberDigiV2AssociationCollection output_digi_sim_association;
+    extension::DriftChamberDigiV2Collection output_digi_hits;
+    extension::MCRecoDriftChamberDigiV2AssociationCollection output_digi_sim_association;
 
     //loop over hit collection
     for (const auto& input_sim_hit : input_sim_hits)
@@ -162,7 +162,7 @@ DCHdigi::operator()(const edm4hep::SimTrackerHitCollection& input_sim_hits,
 
         auto [clusterCount,clusterSize] = CalculateClusters(input_sim_hit);
 
-        edm4hep::MutableDriftChamberDigiV2 oDCHdigihit;
+        extension::MutableDriftChamberDigiV2 oDCHdigihit;
         oDCHdigihit.setCellID(input_sim_hit.getCellID());
         oDCHdigihit.setType(type);
         oDCHdigihit.setQuality(quality);
@@ -177,7 +177,7 @@ DCHdigi::operator()(const edm4hep::SimTrackerHitCollection& input_sim_hits,
 
         output_digi_hits.push_back(oDCHdigihit);
 
-        edm4hep::MutableMCRecoDriftChamberDigiV2Association oDCHsimdigi_association;
+        extension::MutableMCRecoDriftChamberDigiV2Association oDCHsimdigi_association;
         oDCHsimdigi_association.setDigi( oDCHdigihit  );
         oDCHsimdigi_association.setSim( input_sim_hit  );
         output_digi_sim_association.push_back(oDCHsimdigi_association);
@@ -185,7 +185,7 @@ DCHdigi::operator()(const edm4hep::SimTrackerHitCollection& input_sim_hits,
         }// end loop over hit collection
 
     /////////////////////////////////////////////////////////////////
-    return std::make_tuple<edm4hep::DriftChamberDigiV2Collection,edm4hep::MCRecoDriftChamberDigiV2AssociationCollection>(std::move(output_digi_hits),std::move(output_digi_sim_association));
+    return std::make_tuple<extension::DriftChamberDigiV2Collection,extension::MCRecoDriftChamberDigiV2AssociationCollection>(std::move(output_digi_hits),std::move(output_digi_sim_association));
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////