propertys inherited by entity give error in NamedQuery editor

I Have:

An Entity named invoice. The property mailed is on a parent class.

UPDATE InvoiceEntity a set a.mailed = :newValue WHERE a.id = :id

It works fine when i run it, but is does not work with auto complete and gives me all there errors since it cannot find the properties form the parent class.

Does anybody know how to fix this.