diff --git a/SimG4CMS/CherenkovAnalysis/data/SingleDREAMDD4Hep.xml b/SimG4CMS/CherenkovAnalysis/data/SingleDREAMDD4Hep.xml
index f645f19e9ae33..432001d44fed6 100644
--- a/SimG4CMS/CherenkovAnalysis/data/SingleDREAMDD4Hep.xml
+++ b/SimG4CMS/CherenkovAnalysis/data/SingleDREAMDD4Hep.xml
@@ -21,6 +21,7 @@
 
   <IncludeSection>
    <Include ref='Geometry/CMSCommonData/data/materials/2021/v2/materials.xml'/>
+   <Include ref='SimG4CMS/CherenkovAnalysis/data/cms.xml'/>
    <Include ref='SimG4CMS/CherenkovAnalysis/data/singleDREAM.xml'/>
   </IncludeSection>
 </DDDefinition>
diff --git a/SimG4CMS/CherenkovAnalysis/data/cms.xml b/SimG4CMS/CherenkovAnalysis/data/cms.xml
new file mode 100644
index 0000000000000..7d59d00a2d97e
--- /dev/null
+++ b/SimG4CMS/CherenkovAnalysis/data/cms.xml
@@ -0,0 +1,35 @@
+<?xml version="1.0"?>
+<DDDefinition>
+
+<SolidSection label="cms">
+ <Box name="DREAM"   dx="2.0*m"  dy="0.3*m"  dz="2.0*m"/>
+ <Box name="Crystal" dx="9.0*cm" dy="1.1*cm" dz="1.1*cm"/>
+</SolidSection>
+
+<LogicalPartSection label="cms">
+ <LogicalPart name="OCMS" category="unspecified">
+  <rSolid name="DREAM"/>
+  <rMaterial name="materials:Air"/>
+ </LogicalPart>
+ <LogicalPart name="DREAM" category="unspecified">
+  <rSolid name="DREAM"/>
+  <rMaterial name="materials:Air"/>
+ </LogicalPart>
+ <LogicalPart name="Crystal" category="unspecified">
+  <rSolid name="Crystal"/>
+  <rMaterial name="materials:E_PbWO4"/>
+ </LogicalPart>
+</LogicalPartSection>
+
+<PosPartSection label="cms">
+ <PosPart copyNumber="1">
+   <rParent name="cms:OCMS"/>
+   <rChild name="cms:DREAM"/>
+ </PosPart>
+ <PosPart copyNumber="1">
+   <rParent name="cms:DREAM"/>
+   <rChild name="cms:Crystal"/>
+ </PosPart>
+</PosPartSection>
+
+</DDDefinition>
diff --git a/SimG4CMS/CherenkovAnalysis/data/singleDREAM.xml b/SimG4CMS/CherenkovAnalysis/data/singleDREAM.xml
index 239e87c842921..4186a87f8602f 100644
--- a/SimG4CMS/CherenkovAnalysis/data/singleDREAM.xml
+++ b/SimG4CMS/CherenkovAnalysis/data/singleDREAM.xml
@@ -1,36 +1,6 @@
 <?xml version="1.0"?>
 <DDDefinition>
 
-<SolidSection label="singleDREAM">
- <Box name="DREAM"   dx="2.0*m"  dy="0.3*m"  dz="2.0*m"/>
- <Box name="Crystal" dx="9.0*cm" dy="1.1*cm" dz="1.1*cm"/>
-</SolidSection>
-
-<LogicalPartSection label="singleDREAM">
- <LogicalPart name="World" category="unspecified">
-  <rSolid name="DREAM"/>
-  <rMaterial name="materials:Air"/>
- </LogicalPart>
- <LogicalPart name="DREAM" category="unspecified">
-  <rSolid name="DREAM"/>
-  <rMaterial name="materials:Air"/>
- </LogicalPart>
- <LogicalPart name="Crystal" category="unspecified">
-  <rSolid name="Crystal"/>
-  <rMaterial name="materials:E_PbWO4"/>
- </LogicalPart>
-</LogicalPartSection>
-
-<PosPartSection label="singleDREAM">
- <PosPart copyNumber="1">
-   <rParent name="singleDREAM:World"/>
-   <rChild name="singleDREAM:DREAM"/>
- </PosPart>
- <PosPart copyNumber="1">
-   <rParent name="singleDREAM:DREAM"/>
-   <rChild name="singleDREAM:Crystal"/>
- </PosPart>
-</PosPartSection>
 
 <SpecParSection label="singleDREAM" eval="true">
  <SpecPar name="Crystal">
diff --git a/SimG4CMS/CherenkovAnalysis/python/SingleDREAMXML_cfi.py b/SimG4CMS/CherenkovAnalysis/python/SingleDREAMXML_cfi.py
index f61ed78b83ef9..2e27a6f0581a8 100644
--- a/SimG4CMS/CherenkovAnalysis/python/SingleDREAMXML_cfi.py
+++ b/SimG4CMS/CherenkovAnalysis/python/SingleDREAMXML_cfi.py
@@ -3,8 +3,9 @@
 XMLIdealGeometryESSource = cms.ESSource("XMLIdealGeometryESSource",
     geomXMLFiles = cms.vstring(
         'Geometry/CMSCommonData/data/materials/2021/v2/materials.xml', 
+        'SimG4CMS/CherenkovAnalysis/data/cms.xml',
         'SimG4CMS/CherenkovAnalysis/data/singleDREAM.xml'),
-    rootNodeName = cms.string('singleDREAM:DREAM')
+    rootNodeName = cms.string('cms:OCMS')
 )
 
 
diff --git a/SimG4CMS/CherenkovAnalysis/src/DreamSD.cc b/SimG4CMS/CherenkovAnalysis/src/DreamSD.cc
index 574a98da415c2..57f355729dc12 100644
--- a/SimG4CMS/CherenkovAnalysis/src/DreamSD.cc
+++ b/SimG4CMS/CherenkovAnalysis/src/DreamSD.cc
@@ -1,6 +1,3 @@
-
-#include <memory>
-
 #include "DetectorDescription/Core/interface/DDCompactView.h"
 #include "DetectorDescription/Core/interface/DDFilter.h"
 #include "DetectorDescription/Core/interface/DDFilteredView.h"
@@ -142,11 +139,10 @@ void DreamSD::initMap(const std::string &sd) {
     DDFilteredView fv((*cpvDDD_), filter);
     fv.firstChild();
     bool dodet = true;
-    const G4LogicalVolumeStore *lvs = G4LogicalVolumeStore::GetInstance();
     while (dodet) {
       const DDSolid &sol = fv.logicalPart().solid();
       std::vector<double> paras(sol.parameters());
-      G4String name = sol.name().name();
+      std::string name = static_cast<std::string>(sol.name().name());
 #ifdef EDM_ML_DEBUG
       edm::LogVerbatim("EcalSim") << "DreamSD::initMap (for " << sd << "): Solid " << name << " Shape " << sol.shape()
                                   << " Parameter 0 = " << paras[0];
@@ -155,16 +151,7 @@ void DreamSD::initMap(const std::string &sd) {
       std::sort(paras.begin(), paras.end());
       double length = 2.0 * k_ScaleFromDDDToG4 * paras.back();
       double width = 2.0 * k_ScaleFromDDDToG4 * paras.front();
-      G4LogicalVolume *lv = nullptr;
-      for (auto lvcite = lvs->begin(); lvcite != lvs->end(); lvcite++)
-        if ((*lvcite)->GetName() == name) {
-          lv = (*lvcite);
-          break;
-        }
-      xtalLMap_.insert(std::pair<G4LogicalVolume *, Doubles>(lv, Doubles(length, width)));
-#ifdef EDM_ML_DEBUG
-      edm::LogVerbatim("EcalSim") << "DreamSD " << name << ":" << lv << ":" << length << ":" << width;
-#endif
+      fillMap(name, length, width);
       dodet = fv.next();
     }
   }
@@ -191,7 +178,8 @@ void DreamSD::fillMap(const std::string &name, double length, double width) {
   G4LogicalVolume *lv = nullptr;
   for (auto lvcite = lvs->begin(); lvcite != lvs->end(); lvcite++) {
     edm::LogVerbatim("EcalSim") << name << " vs " << (*lvcite)->GetName();
-    if ((*lvcite)->GetName() == static_cast<G4String>(name)) {
+    std::string namex = static_cast<std::string>((*lvcite)->GetName());
+    if (name == static_cast<std::string>(dd4hep::dd::noNamespace(namex))) {
       lv = (*lvcite);
       break;
     }
@@ -432,7 +420,8 @@ double DreamSD::getAverageNumberOfPhotons_(const double charge,
 // Values from Ts42 detector construction
 bool DreamSD::setPbWO2MaterialProperties_(G4Material *aMaterial) {
   std::string pbWO2Name("E_PbWO4");
-  if (pbWO2Name != aMaterial->GetName()) {  // Wrong material!
+  std::string name = static_cast<std::string>(aMaterial->GetName());
+  if (static_cast<std::string>(dd4hep::dd::noNamespace(name)) != pbWO2Name) {  // Wrong material!
     edm::LogWarning("EcalSim") << "This is not the right material: "
                                << "expecting " << pbWO2Name << ", got " << aMaterial->GetName();
     return false;
diff --git a/SimG4CMS/CherenkovAnalysis/test/runSingleDREAMDD4Hep_cfg.py b/SimG4CMS/CherenkovAnalysis/test/runSingleDREAMDD4Hep_cfg.py
index 4dee50fee0ade..e4069a5951fbe 100644
--- a/SimG4CMS/CherenkovAnalysis/test/runSingleDREAMDD4Hep_cfg.py
+++ b/SimG4CMS/CherenkovAnalysis/test/runSingleDREAMDD4Hep_cfg.py
@@ -39,7 +39,6 @@
 process.p1 = cms.Path(process.generator*process.VtxSmeared*process.generatorSmeared*process.g4SimHits*process.cherenkovAnalysis)
 
 process.DDDetectorESProducer.confGeomXMLFiles = cms.FileInPath("SimG4CMS/CherenkovAnalysis/data/SingleDREAMDD4Hep.xml")
-process.DDDetectorESProducer.rootDDName = 'singleDREAM:DREAM'
 process.generator.PGunParameters.MinE = 10.0
 process.generator.PGunParameters.MaxE = 10.0
 process.g4SimHits.UseMagneticField = False