diff --git a/src/SMESH/SMESH_Mesh.cxx b/src/SMESH/SMESH_Mesh.cxx
index eeba23c89..5f108cc3b 100644
--- a/src/SMESH/SMESH_Mesh.cxx
+++ b/src/SMESH/SMESH_Mesh.cxx
@@ -524,6 +524,8 @@ SMESH_Hypothesis::Hypothesis_Status
   }
   HasModificationsToDiscard(); // to reset _isModified flag if a mesh becomes empty
 
+  GetMeshDS()->Modified();
+
   if(MYDEBUG) subMesh->DumpAlgoState(true);
   if(MYDEBUG) SCRUTE(ret);
   return ret;
@@ -597,6 +599,8 @@ SMESH_Hypothesis::Hypothesis_Status
 
   HasModificationsToDiscard(); // to reset _isModified flag if mesh become empty
 
+  GetMeshDS()->Modified();
+
   if(MYDEBUG) subMesh->DumpAlgoState(true);
   if(MYDEBUG) SCRUTE(ret);
   return ret;