diff --git a/src/SMESHGUI/SMESHGUI_aParameterDlg.cxx b/src/SMESHGUI/SMESHGUI_aParameterDlg.cxx
index b9c9f1d3b..211b4f0ec 100644
--- a/src/SMESHGUI/SMESHGUI_aParameterDlg.cxx
+++ b/src/SMESHGUI/SMESHGUI_aParameterDlg.cxx
@@ -119,6 +119,7 @@ void SMESHGUI_aParameterDlg::init()
   }
 
   myPreview = new SMESHGUI_FunctionPreview( GroupC1 );
+  myPreview->hide();
   GroupC1Layout->addWidget( myPreview, row, 1 );
 
   paramIt = myParamList.begin();
diff --git a/src/StdMeshersGUI/StdMeshersGUI_CreateHypothesisDlg.cxx b/src/StdMeshersGUI/StdMeshersGUI_CreateHypothesisDlg.cxx
index b43492f5d..d93e8c2fe 100644
--- a/src/StdMeshersGUI/StdMeshersGUI_CreateHypothesisDlg.cxx
+++ b/src/StdMeshersGUI/StdMeshersGUI_CreateHypothesisDlg.cxx
@@ -163,6 +163,7 @@ void StdMeshersGUI_CreateHypothesisDlg::CreateDlgLayout(const QString & theCapti
     }
   }
   myPreview = new SMESHGUI_FunctionPreview( GroupC1 );
+  myPreview->hide();
   GroupC1Layout->addWidget( myPreview, row, 1 );
   
   StdMeshersGUI_CreateHypothesisDlgLayout->addWidget( GroupC1, 1 );