diff --git a/src/DriverMED/DriverMED_R_SMESHDS_Mesh.cxx b/src/DriverMED/DriverMED_R_SMESHDS_Mesh.cxx
index ac7cb640f..fac44fc86 100644
--- a/src/DriverMED/DriverMED_R_SMESHDS_Mesh.cxx
+++ b/src/DriverMED/DriverMED_R_SMESHDS_Mesh.cxx
@@ -270,7 +270,7 @@ Driver_Mesh::Status DriverMED_R_SMESHDS_Mesh::Perform()
               aNodeIds.assign( aBallInfo->myConn->begin(), aBallInfo->myConn->end());
 
             // allocate array of diameters
-            vtkIdType maxID = myMesh->MaxElementID() + aNbBalls;
+            vtkIdType maxID = FromIdType<vtkIdType>(myMesh->MaxElementID() + aNbBalls);
             if ( anIsElemNum && !aBallInfo->myElemNum->empty() )
               maxID = *std::max_element( aBallInfo->myElemNum->begin(),
                                          aBallInfo->myElemNum->end() );
diff --git a/src/SMDS/SMDS_ElementFactory.cxx b/src/SMDS/SMDS_ElementFactory.cxx
index 1c9a3cbe3..4ac7ca9aa 100644
--- a/src/SMDS/SMDS_ElementFactory.cxx
+++ b/src/SMDS/SMDS_ElementFactory.cxx
@@ -178,11 +178,11 @@ SMDS_MeshElement* SMDS_ElementFactory::NewElement( const smIdType id )
     smIdType id0 = myChunks.size() * theChunkSize + 1;
     myChunks.push_back( new SMDS_ElementChunk( this, id0 ));
   }
-  SMDS_MeshElement* e = myChunks[iChunk].Element( index );
+  SMDS_MeshElement* e = myChunks[iChunk].Element( FromIdType<int>(index) );
   if ( !e->IsNull() )
     return 0; // element with given ID already exists
 
-  myChunks[iChunk].UseElement( index );
+  myChunks[iChunk].UseElement( FromIdType<int>(index) );
   ++myNbUsedElements;
 
   e->myHolder = & myChunks[iChunk];
@@ -208,7 +208,7 @@ const SMDS_MeshElement* SMDS_ElementFactory::FindElement( const smIdType id ) co
     smIdType index  = ( id - 1 ) % theChunkSize;
     if ( iChunk < (smIdType) myChunks.size() )
     {
-      const SMDS_MeshElement* e = myChunks[iChunk].Element( index );
+      const SMDS_MeshElement* e = myChunks[iChunk].Element( FromIdType<int>(index) );
       return e->IsNull() ? 0 : e;
     }
   }
@@ -314,7 +314,7 @@ void SMDS_ElementFactory::Compact( std::vector<smIdType>& theVtkIDsNewToOld )
         const SMDS_MeshElement* newElem = FindElement( newVtkID );
         if ( !newElem )
           newElem = NewElement( newVtkID );
-        if ( smIdType shapeID = oldElem->GetShapeID() )
+        if ( int shapeID = oldElem->GetShapeID() )
           const_cast< SMDS_MeshElement* >( newElem )->setShapeID( shapeID );
         if ( oldID > newNbCells )
           Free( oldElem );
@@ -584,7 +584,7 @@ smIdType SMDS_ElementChunk::GetUnusedID() const
 void SMDS_ElementChunk::Free( const SMDS_MeshElement* e )
 {
   bool hasHoles = ( myUsedRanges.Size() > 1 );
-  myUsedRanges.SetValue( Index( e ), false );
+  myUsedRanges.SetValue( FromIdType<int>(Index( e )), false );
   SetShapeID( e, 0 ); // sub-mesh must do it?
   SetIsMarked( e, false );
   if ( !hasHoles )
@@ -646,7 +646,7 @@ void SMDS_ElementChunk::SetVTKID( const SMDS_MeshElement* e, const vtkIdType vtk
 
 vtkIdType SMDS_ElementChunk::GetVtkID( const SMDS_MeshElement* e ) const
 {
-  vtkIdType dfltVtkID = e->GetID() - 1;
+  vtkIdType dfltVtkID = FromIdType<vtkIdType>(e->GetID() - 1);
   return ( dfltVtkID < (vtkIdType)myFactory->myVtkIDs.size() ) ? myFactory->myVtkIDs[ dfltVtkID ] : dfltVtkID;
 }
 
@@ -658,7 +658,7 @@ vtkIdType SMDS_ElementChunk::GetVtkID( const SMDS_MeshElement* e ) const
 
 int SMDS_ElementChunk::GetShapeID( const SMDS_MeshElement* e ) const
 {
-  return mySubIDRanges.GetValue( Index( e ));
+  return mySubIDRanges.GetValue( FromIdType<int>(Index( e )));
 }
 
 //================================================================================
@@ -672,7 +672,7 @@ void SMDS_ElementChunk::SetShapeID( const SMDS_MeshElement* e, int shapeID ) con
   //const size_t nbRanges = mySubIDRanges.Size();
 
   SMDS_ElementChunk* me = const_cast<SMDS_ElementChunk*>( this );
-  int oldShapeID = me->mySubIDRanges.SetValue( Index( e ), shapeID );
+  int oldShapeID = me->mySubIDRanges.SetValue( FromIdType<int>(Index( e )), shapeID );
   if ( oldShapeID == shapeID ) return;
 
   if ( const SMDS_MeshNode* n = dynamic_cast< const SMDS_MeshNode* >( e ))
diff --git a/src/SMDS/SMDS_Mesh.cxx b/src/SMDS/SMDS_Mesh.cxx
index 52bd75e80..f2934ce25 100644
--- a/src/SMDS/SMDS_Mesh.cxx
+++ b/src/SMDS/SMDS_Mesh.cxx
@@ -815,9 +815,9 @@ SMDS_MeshVolume* SMDS_Mesh::AddVolumeWithID(const SMDS_MeshNode * n1,
 SMDS_MeshFace* SMDS_Mesh::AddPolygonalFaceWithID (const std::vector<smIdType> & nodes_ids,
                                                   const smIdType               ID)
 {
-  int nbNodes = nodes_ids.size();
+  smIdType nbNodes = nodes_ids.size();
   std::vector<const SMDS_MeshNode*> nodes (nbNodes);
-  for (int i = 0; i < nbNodes; i++) {
+  for (smIdType i = 0; i < nbNodes; i++) {
     nodes[i] = myNodeFactory->FindNode( nodes_ids[i] );
     if (!nodes[i]) return NULL;
   }
@@ -911,9 +911,9 @@ SMDS_MeshVolume * SMDS_Mesh::AddPolyhedralVolumeWithID (const std::vector<smIdTy
                                                         const std::vector<int>      & quantities,
                                                         const smIdType                ID)
 {
-  int nbNodes = nodes_ids.size();
+  smIdType nbNodes = nodes_ids.size();
   std::vector<const SMDS_MeshNode*> nodes (nbNodes);
-  for (int i = 0; i < nbNodes; i++) {
+  for (smIdType i = 0; i < nbNodes; i++) {
     nodes[i] = myNodeFactory->FindNode(nodes_ids[i]);
     if (!nodes[i]) return NULL;
   }
diff --git a/src/SMDS/SMDS_UnstructuredGrid.cxx b/src/SMDS/SMDS_UnstructuredGrid.cxx
index 6ce4bb03b..ca5b300bf 100644
--- a/src/SMDS/SMDS_UnstructuredGrid.cxx
+++ b/src/SMDS/SMDS_UnstructuredGrid.cxx
@@ -298,16 +298,16 @@ void SMDS_UnstructuredGrid::compactGrid(std::vector<smIdType>& idNodesOldToNew,
       {
         smIdType oldCellId = idCellsNewToOld[ newCellID ];
         newFaceLocations->InsertNextValue( newFaces->GetMaxId()+1 );
-        smIdType oldFaceLoc = this->FaceLocations->GetValue( oldCellId );
-        smIdType nCellFaces = this->Faces->GetValue( oldFaceLoc++ );
-        newFaces->InsertNextValue( nCellFaces );
+        smIdType oldFaceLoc = this->FaceLocations->GetValue( FromIdType<int>(oldCellId) );
+        smIdType nCellFaces = this->Faces->GetValue( FromIdType<int>(oldFaceLoc++) );
+        newFaces->InsertNextValue( FromIdType<int>(nCellFaces) );
         for ( int n = 0; n < nCellFaces; n++ )
         {
-          int nptsInFace = this->Faces->GetValue( oldFaceLoc++ );
+          int nptsInFace = this->Faces->GetValue( FromIdType<int>(oldFaceLoc++) );
           newFaces->InsertNextValue( nptsInFace );
           for ( int k = 0; k < nptsInFace; k++ )
           {
-            vtkIdType oldpt = this->Faces->GetValue( oldFaceLoc++ );
+            vtkIdType oldpt = this->Faces->GetValue( FromIdType<int>(oldFaceLoc++) );
             newFaces->InsertNextValue( idNodesOldToNew[ oldpt ]);
           }
         }
diff --git a/src/SMESHDS/SMESHDS_GroupBase.cxx b/src/SMESHDS/SMESHDS_GroupBase.cxx
index 50ac2ee74..e6a9799be 100644
--- a/src/SMESHDS/SMESHDS_GroupBase.cxx
+++ b/src/SMESHDS/SMESHDS_GroupBase.cxx
@@ -64,7 +64,7 @@ int SMESHDS_GroupBase::GetID (const int theIndex)
   }
   while (myCurIndex < theIndex && myIterator->more()) {
     myCurIndex++;
-    myCurID = myIterator->next()->GetID();
+    myCurID = FromIdType<int>(myIterator->next()->GetID());
   }
   return myCurIndex == theIndex ? myCurID : -1;
 }
@@ -154,7 +154,7 @@ bool SMESHDS_GroupBase::Contains (const int theID)
 bool SMESHDS_GroupBase::Contains (const SMDS_MeshElement* elem)
 {
   if ( elem )
-    return Contains( elem->GetID() );
+    return Contains( FromIdType<int>(elem->GetID()) );
   return false;
 }
 
diff --git a/src/SMESHDS/SMESHDS_GroupOnFilter.cxx b/src/SMESHDS/SMESHDS_GroupOnFilter.cxx
index 3d8f98fc9..e11f228c0 100644
--- a/src/SMESHDS/SMESHDS_GroupOnFilter.cxx
+++ b/src/SMESHDS/SMESHDS_GroupOnFilter.cxx
@@ -315,7 +315,7 @@ int SMESHDS_GroupOnFilter::getElementIds( void* ids, size_t idSize ) const
     if ( IsUpToDate() )
     {
       for ( ; elIt->more(); curID += idSize )
-        (*(int*) curID) = elIt->next()->GetID();
+        (*(int*) curID) = FromIdType<int>(elIt->next()->GetID());
     }
     else
     {
@@ -325,11 +325,11 @@ int SMESHDS_GroupOnFilter::getElementIds( void* ids, size_t idSize ) const
       me->myMeshInfo.assign( SMDSEntity_Last, 0 );
       me->myMeshInfo[ firstOkElem->GetEntityType() ]++;
 
-      (*(int*) curID) = firstOkElem->GetID();
+      (*(int*) curID) = FromIdType<int>(firstOkElem->GetID());
       for ( curID += idSize; elIt->more(); curID += idSize )
       {
         const SMDS_MeshElement* e = elIt->next();
-        (*(int*) curID) = e->GetID();
+        (*(int*) curID) = FromIdType<int>(e->GetID());
         me->myMeshInfo[ e->GetEntityType() ]++;
       }
     }
@@ -443,7 +443,7 @@ bool SMESHDS_GroupOnFilter::updateParallel() const
     return false; // no sense in parallel work
 
   SMDS_ElemIteratorPtr elemIt = GetMesh()->elementsIterator( GetType() );
-  const int minID = elemIt->next()->GetID();
+  const smIdType minID = elemIt->next()->GetID();
   myPredicate->IsSatisfy( minID ); // make myPredicate fully initialized for clone()
   SMESH_PredicatePtr clone( myPredicate->clone() );
   if ( !clone )
@@ -452,7 +452,7 @@ bool SMESHDS_GroupOnFilter::updateParallel() const
   TLocalPredicat threadPredicates;
   threadPredicates.local() = clone;
 
-  int maxID = ( GetType() == SMDSAbs_Node ) ? GetMesh()->MaxNodeID() : GetMesh()->MaxElementID();
+  smIdType maxID = ( GetType() == SMDSAbs_Node ) ? GetMesh()->MaxNodeID() : GetMesh()->MaxElementID();
   vector< char > isElemOK( 1 + maxID );
 
   tbb::parallel_for ( tbb::blocked_range<size_t>( 0, isElemOK.size() ),
diff --git a/src/SMESHUtils/SMESH_MeshAlgos.cxx b/src/SMESHUtils/SMESH_MeshAlgos.cxx
index 3bc48ff24..c5bed4dad 100644
--- a/src/SMESHUtils/SMESH_MeshAlgos.cxx
+++ b/src/SMESHUtils/SMESH_MeshAlgos.cxx
@@ -281,7 +281,7 @@ namespace // Utils used in SMESH_ElementSearcherImpl::FindElementsByPoint()
                                        double               tolerance)
     :SMESH_Octree( new LimitAndPool() )
   {
-    int nbElems = mesh.GetMeshInfo().NbElements( elemType );
+    smIdType nbElems = mesh.GetMeshInfo().NbElements( elemType );
     _elements.reserve( nbElems );
 
     TElementBoxPool& elBoPool = getLimitAndPool()->_elBoPool;
@@ -1981,7 +1981,7 @@ SMESH_MeshAlgos::FindSharpEdges( SMDS_Mesh* theMesh,
   typedef std::pair< bool, const SMDS_MeshNode* >                            TIsSharpAndMedium;
   typedef NCollection_DataMap< SMESH_TLink, TIsSharpAndMedium, SMESH_TLink > TLinkSharpMap;
 
-  TLinkSharpMap linkIsSharp( theMesh->NbFaces() );
+  TLinkSharpMap linkIsSharp( FromIdType<int>(theMesh->NbFaces()) );
   TIsSharpAndMedium sharpMedium( true, 0 );
   bool                 & isSharp = sharpMedium.first;
   const SMDS_MeshNode* & nMedium = sharpMedium.second;
@@ -2088,7 +2088,7 @@ SMESH_MeshAlgos::SeparateFacesByEdges( SMDS_Mesh* theMesh, const std::vector< Ed
 
   typedef std::vector< const SMDS_MeshElement* >                    TFaceVec;
   typedef NCollection_DataMap< SMESH_TLink, TFaceVec, SMESH_TLink > TFacesByLinks;
-  TFacesByLinks facesByLink( theMesh->NbFaces() );
+  TFacesByLinks facesByLink( FromIdType<int>(theMesh->NbFaces()) );
 
   std::vector< const SMDS_MeshNode* > faceNodes;
   for ( SMDS_FaceIteratorPtr faceIt = theMesh->facesIterator(); faceIt->more(); )
diff --git a/src/SMESHUtils/SMESH_Offset.cxx b/src/SMESHUtils/SMESH_Offset.cxx
index 97e299261..914c68241 100644
--- a/src/SMESHUtils/SMESH_Offset.cxx
+++ b/src/SMESHUtils/SMESH_Offset.cxx
@@ -1933,7 +1933,7 @@ namespace SMESH_MeshAlgos
       for ( ; cutFacesIt != myCutFaces.cend(); ++cutFacesIt )
       {
         const CutFace& cf = *cutFacesIt;
-        int index = cf.myInitFace->GetID(); // index in theNew2OldFaces
+        smIdType index = cf.myInitFace->GetID(); // index in theNew2OldFaces
         if ((int) theNew2OldFaces.size() <= index )
           theNew2OldFaces.resize( index + 1 );
         theNew2OldFaces[ index ] = std::make_pair( cf.myInitFace, index );
@@ -2004,7 +2004,7 @@ namespace SMESH_MeshAlgos
       // erase loops that are cut off by face intersections
       cf.CutOffLoops( loopSet, theSign, myNormals, cutOffLinks, cutOffCoplanarLinks );
 
-      int index = cf.myInitFace->GetID(); // index in theNew2OldFaces
+      smIdType index = cf.myInitFace->GetID(); // index in theNew2OldFaces
 
       const SMDS_MeshElement* tria;
       for ( size_t iL = 0; iL < loopSet.myNbLoops; ++iL )
@@ -2094,7 +2094,7 @@ namespace SMESH_MeshAlgos
           continue;
         for ( size_t iF = 0; iF < faces.size(); ++iF )
         {
-          int index = faces[iF]->GetID();
+          smIdType index = faces[iF]->GetID();
           // if ( //faces[iF]->isMarked()         ||  // kept part of cutFace
           //      !theNew2OldFaces[ index ].first ) // already removed
           //   continue;
@@ -2126,7 +2126,7 @@ namespace SMESH_MeshAlgos
       if ( cf.myInitFace->IsNull() )
         continue;
 
-      int index = cf.myInitFace->GetID(); // index in theNew2OldFaces
+      smIdType index = cf.myInitFace->GetID(); // index in theNew2OldFaces
       if ( !theNew2OldFaces[ index ].first )
         continue; // already cut off
 
@@ -3226,7 +3226,7 @@ SMDS_Mesh* SMESH_MeshAlgos::MakeOffset( SMDS_ElemIteratorPtr theFaceIt,
     for ( SMDS_ElemIteratorPtr fIt = newNode->GetInverseElementIterator(); fIt->more(); )
     {
       const SMDS_MeshElement* newFace = fIt->next();
-      const int             faceIndex = newFace->GetID();
+      const int             faceIndex = FromIdType<int>(newFace->GetID());
       const gp_XYZ&           oldNorm = normals[ faceIndex ];
       const gp_XYZ             newXYZ = oldXYZ + oldNorm * theOffset;
       if ( multiPos.empty() )
@@ -3275,7 +3275,7 @@ SMDS_Mesh* SMESH_MeshAlgos::MakeOffset( SMDS_ElemIteratorPtr theFaceIt,
       for ( SMDS_ElemIteratorPtr fIt = newNode->GetInverseElementIterator(); fIt->more(); )
       {
         const SMDS_MeshElement* newFace = fIt->next();
-        const int             faceIndex = newFace->GetID();
+        const int             faceIndex = FromIdType<int>(newFace->GetID());
         const gp_XYZ&           oldNorm = normals[ faceIndex ];
         if ( !SMESH_MeshAlgos::FaceNormal( newFace, faceNorm, /*normalize=*/false ) ||
              //faceNorm * moveVec < 0 )
diff --git a/src/SMESHUtils/SMESH_Slot.cxx b/src/SMESHUtils/SMESH_Slot.cxx
index 33c16aa27..910ef74f0 100644
--- a/src/SMESHUtils/SMESH_Slot.cxx
+++ b/src/SMESHUtils/SMESH_Slot.cxx
@@ -391,7 +391,7 @@ namespace
         theWorkGroups.push_back( theGroupsToUpdate[i] );
 
     if ( !theWorkGroups.empty() )
-      theFaceID2Groups.Bind( theFace->GetID(), theWorkGroups );
+      theFaceID2Groups.Bind( FromIdType<int>(theFace->GetID()), theWorkGroups );
   }
 
   //================================================================================