diff --git a/src/OBJECT/SMESH_Object.h b/src/OBJECT/SMESH_Object.h
index 9e2f49dcf..0366866b5 100644
--- a/src/OBJECT/SMESH_Object.h
+++ b/src/OBJECT/SMESH_Object.h
@@ -55,7 +55,7 @@ class vtkUnstructuredGrid;
 class SMESHOBJECT_EXPORT SMESH_VisualObj
 {
 public:
-  virtual void Update( int theIsClear = true ) = 0;
+  virtual bool Update( int theIsClear = true ) = 0;
   virtual void UpdateFunctor( const SMESH::Controls::FunctorPtr& theFunctor ) = 0;
   virtual int GetElemDimension( const int theObjId ) = 0;
 
diff --git a/src/OBJECT/SMESH_ObjectDef.h b/src/OBJECT/SMESH_ObjectDef.h
index 327664867..7c8ba5480 100644
--- a/src/OBJECT/SMESH_ObjectDef.h
+++ b/src/OBJECT/SMESH_ObjectDef.h
@@ -61,7 +61,7 @@ public:
                             SMESH_VisualObjDef();
   virtual                   ~SMESH_VisualObjDef();
   
-  virtual void              Update( int theIsClear = true ) = 0;
+  virtual bool              Update( int theIsClear = true ) = 0;
   virtual void              UpdateFunctor( const SMESH::Controls::FunctorPtr& theFunctor ) = 0;
   virtual int               GetElemDimension( const int theObjId ) = 0;
 
@@ -112,7 +112,7 @@ public:
                             SMESH_MeshObj( SMESH::SMESH_Mesh_ptr );
   virtual                   ~SMESH_MeshObj();
   
-  virtual void              Update( int theIsClear = true );
+  virtual bool              Update( int theIsClear = true );
   
   virtual int               GetNbEntities( const SMDSAbs_ElementType) const;
   virtual int               GetEntities( const SMDSAbs_ElementType, TEntityList& ) const;
@@ -142,7 +142,7 @@ public:
                             SMESH_SubMeshObj(SMESH_MeshObj* theMeshObj);
   virtual                   ~SMESH_SubMeshObj();
 
-  virtual void              Update( int theIsClear = true );
+  virtual bool              Update( int theIsClear = true );
   
   virtual void              UpdateFunctor( const SMESH::Controls::FunctorPtr& theFunctor );
   virtual int               GetElemDimension( const int theObjId );