diff --git a/SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h b/SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h
deleted file mode 100644
index c03a582548b1f..0000000000000
--- a/SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#ifndef SimG4Core_PhysicsLists_CMSThermalNeutrons_h
-#define SimG4Core_PhysicsLists_CMSThermalNeutrons_h
-
-#include "G4VHadronPhysics.hh"
-#include "globals.hh"
-
-class CMSThermalNeutrons : public G4VHadronPhysics {
-public:
-  CMSThermalNeutrons(G4int ver);
-  ~CMSThermalNeutrons() override;
-
-  void ConstructProcess() override;
-
-private:
-  G4int verbose;
-};
-
-#endif
diff --git a/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EML.cc b/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EML.cc
index 6573516bd0fd2..2d100c6a1bd8f 100644
--- a/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EML.cc
+++ b/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EML.cc
@@ -1,8 +1,8 @@
 #include "FTFPCMS_BERT_HP_EML.h"
 #include "SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsXS.h"
-#include "SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h"
 #include "FWCore/MessageLogger/interface/MessageLogger.h"
 
+#include "G4ThermalNeutrons.hh"
 #include "G4DecayPhysics.hh"
 #include "G4EmExtraPhysics.hh"
 #include "G4IonPhysics.hh"
@@ -60,7 +60,7 @@ FTFPCMS_BERT_HP_EML::FTFPCMS_BERT_HP_EML(const edm::ParameterSet& p) : PhysicsLi
       RegisterPhysics(ncut);
     }
     if (thermal) {
-      RegisterPhysics(new CMSThermalNeutrons(ver));
+      RegisterPhysics(new G4ThermalNeutrons(ver));
     }
   }
 }
diff --git a/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EMM.cc b/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EMM.cc
index 0b0df3c35bb2f..60701397b216f 100644
--- a/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EMM.cc
+++ b/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_HP_EMM.cc
@@ -1,8 +1,8 @@
 #include "FTFPCMS_BERT_HP_EMM.h"
 #include "SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsLPM.h"
-#include "SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h"
 #include "FWCore/MessageLogger/interface/MessageLogger.h"
 
+#include "G4ThermalNeutrons.hh"
 #include "G4DecayPhysics.hh"
 #include "G4EmExtraPhysics.hh"
 #include "G4IonPhysics.hh"
@@ -60,7 +60,7 @@ FTFPCMS_BERT_HP_EMM::FTFPCMS_BERT_HP_EMM(const edm::ParameterSet& p) : PhysicsLi
       RegisterPhysics(ncut);
     }
     if (thermal) {
-      RegisterPhysics(new CMSThermalNeutrons(ver));
+      RegisterPhysics(new G4ThermalNeutrons(ver));
     }
   }
 }
diff --git a/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_XS_EML.cc b/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_XS_EML.cc
index e313e8b2de24d..2b67896c4fe24 100644
--- a/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_XS_EML.cc
+++ b/SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_XS_EML.cc
@@ -1,8 +1,8 @@
 #include "FTFPCMS_BERT_XS_EML.h"
 #include "SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsXS.h"
-#include "SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h"
 #include "FWCore/MessageLogger/interface/MessageLogger.h"
 
+#include "G4ThermalNeutrons.hh"
 #include "G4DecayPhysics.hh"
 #include "G4EmExtraPhysics.hh"
 #include "G4IonPhysics.hh"
@@ -60,7 +60,7 @@ FTFPCMS_BERT_XS_EML::FTFPCMS_BERT_XS_EML(const edm::ParameterSet& p) : PhysicsLi
       RegisterPhysics(ncut);
     }
     if (thermal) {
-      RegisterPhysics(new CMSThermalNeutrons(ver));
+      RegisterPhysics(new G4ThermalNeutrons(ver));
     }
   }
 }
diff --git a/SimG4Core/PhysicsLists/plugins/FTFPCMS_INCLXX_HP_EMM.cc b/SimG4Core/PhysicsLists/plugins/FTFPCMS_INCLXX_HP_EMM.cc
index b3088d1b0e759..6c5cc9dacea4d 100644
--- a/SimG4Core/PhysicsLists/plugins/FTFPCMS_INCLXX_HP_EMM.cc
+++ b/SimG4Core/PhysicsLists/plugins/FTFPCMS_INCLXX_HP_EMM.cc
@@ -1,8 +1,8 @@
 #include "FTFPCMS_INCLXX_HP_EMM.h"
 #include "SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsLPM.h"
-#include "SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h"
 #include "FWCore/MessageLogger/interface/MessageLogger.h"
 
+#include "G4ThermalNeutrons.hh"
 #include "G4DecayPhysics.hh"
 #include "G4EmExtraPhysics.hh"
 #include "G4IonINCLXXPhysics.hh"
@@ -60,7 +60,7 @@ FTFPCMS_INCLXX_HP_EMM::FTFPCMS_INCLXX_HP_EMM(const edm::ParameterSet& p) : Physi
       RegisterPhysics(ncut);
     }
     if (thermal) {
-      RegisterPhysics(new CMSThermalNeutrons(ver));
+      RegisterPhysics(new G4ThermalNeutrons(ver));
     }
   }
 }
diff --git a/SimG4Core/PhysicsLists/src/CMSThermalNeutrons.cc b/SimG4Core/PhysicsLists/src/CMSThermalNeutrons.cc
deleted file mode 100644
index b26487438067d..0000000000000
--- a/SimG4Core/PhysicsLists/src/CMSThermalNeutrons.cc
+++ /dev/null
@@ -1,38 +0,0 @@
-#include "SimG4Core/PhysicsLists/interface/CMSThermalNeutrons.h"
-
-#include "G4ParticleDefinition.hh"
-#include "G4ProcessManager.hh"
-#include "G4HadronicProcess.hh"
-
-#include "G4ParticleHPThermalScattering.hh"
-#include "G4ParticleHPThermalScatteringData.hh"
-
-#include "G4BuilderType.hh"
-
-#include "G4SystemOfUnits.hh"
-
-CMSThermalNeutrons::CMSThermalNeutrons(G4int ver) : G4VHadronPhysics("CMSThermalNeutrons"), verbose(ver) {}
-
-CMSThermalNeutrons::~CMSThermalNeutrons() {}
-
-void CMSThermalNeutrons::ConstructProcess() {
-  if (verbose > 0) {
-    G4cout << "### " << GetPhysicsName() << " Construct Processes " << G4endl;
-  }
-  G4Neutron* part = G4Neutron::Neutron();
-  G4HadronicProcess* hpel = FindElasticProcess(part);
-  if (!hpel) {
-    G4cout << "### " << GetPhysicsName() << " WARNING: Fail to add thermal neutron scattering" << G4endl;
-    return;
-  }
-
-  G4int ni = (hpel->GetHadronicInteractionList()).size();
-  if (ni < 1) {
-    G4cout << "### " << GetPhysicsName() << " WARNING: Fail to add thermal neutron scattering - Nint= " << ni << G4endl;
-    return;
-  }
-  (hpel->GetHadronicInteractionList())[ni - 1]->SetMinEnergy(4 * CLHEP::eV);
-
-  hpel->RegisterMe(new G4ParticleHPThermalScattering());
-  hpel->AddDataSet(new G4ParticleHPThermalScatteringData());
-}