diff --git a/DDDetectors/src/SubdetectorAssembly_geo.cpp b/DDDetectors/src/SubdetectorAssembly_geo.cpp
index 2da42cf8a904feb6e39ad74e9b0da7993e51d038..e15f5225ca22189832a9e555a62c8cc43d359c92 100644
--- a/DDDetectors/src/SubdetectorAssembly_geo.cpp
+++ b/DDDetectors/src/SubdetectorAssembly_geo.cpp
@@ -75,7 +75,10 @@ static Ref_t create_element(LCDD& lcdd, xml_h e, Ref_t)  {
     pv = mother.placeVolume( vol );
   }
 
+  pv.addPhysVolID("system", sdet.id() );
+  
   sdet.setPlacement(pv);
+  
   return sdet;
 }