Hide Ribbon on Workbook Open

I'm using this code to hide the ribbon when my workbook opens, but how do I make it unique to this workbook only? At the moment, the ribbon appears hidden in all workbooks.

Private Sub Workbook_Open()
    Application.ExecuteExcel4Macro "Show.Toolbar(""Ribbon"",False)"
End Sub

Private Sub Workbook_Close()
    Application.ExecuteExcel4Macro "Show.Toolbar(""Ribbon"",True)"
End Sub