diff --git a/DDG4/include/DDG4/DDG4Dict.h b/DDG4/include/DDG4/DDG4Dict.h
index cb52beefd6032e6822686eb00be35cca41281099..463ef1a656a81deb40c17ccce01f4a276f00dc95 100644
--- a/DDG4/include/DDG4/DDG4Dict.h
+++ b/DDG4/include/DDG4/DDG4Dict.h
@@ -64,7 +64,6 @@ namespace { class DDG4Dict {};   }
 
 /// Dictionaires for Geant4 particles
 #pragma link C++ class dd4hep::sim::ParticleExtension+;
-#pragma link C++ class std::unique_ptr<dd4hep::sim::ParticleExtension>+;
 
 /// Auto-pointers related. ROOT cannot handle I/O!
 #pragma link C++ class dd4hep::dd4hep_ptr<dd4hep::sim::DataExtension>;
diff --git a/DDG4/include/DDG4/Geant4Data.h b/DDG4/include/DDG4/Geant4Data.h
index 24e69275eea0730111be119bd2b762f3af32ddec..38757cf1266c80233902599dce2cd9709aee3e03 100644
--- a/DDG4/include/DDG4/Geant4Data.h
+++ b/DDG4/include/DDG4/Geant4Data.h
@@ -15,12 +15,12 @@
 #define DDG4_GEANT4DATA_H
 
 // Framework include files
-#include <DD4hep/Memory.h>
 #include <Math/Vector3D.h>
 
 // C/C++ include files
 #include <set>
 #include <vector>
+#include <memory>
 
 // Forward declarations
 class G4Step;
@@ -127,7 +127,7 @@ namespace dd4hep {
       /// Original Geant 4 track identifier of the creating track (debugging)
       long g4ID = -1;
       /// User data extension if required
-      dd4hep_ptr<DataExtension> extension;   //! not persisten. ROOT cannot handle
+      std::unique_ptr<DataExtension> extension;
 
       /// Utility class describing the monte carlo contribution of a given particle to a hit.
       /**