How to make BaseEntity.Id property not to be mapped to table's attribute in a database?

Hi,

I am developing a plugin and I have an object derived from BaseEntity. That object represents a junction table (table that maps many-to-many) in database.
I want the table not to contain Id attribute (that comes from BaseEntity.Id property).

In my class the base Id property is hidden and an attribute NotMapped is applied:

public class MyObject : BaseEntity
{
  [NotMapped]
  public new int Id { get; set; }
}

Also in my Map class I've ignored the property:

public class MyObjectMap : EntityTypeConfiguration<MyObject>
{
  public MyObjectMap()
  {
    ToTable("MyObject");

    ... 
    Ignore(x => x.Id);
  }
}

And my problem is that this property still is added as attribute into the table.

Does someone know how to make the property not to be added as attribute into the table?

Regards,
Boris