Can't ship zero quantity on pack list

Can't ship zero quantity on pack list

I have a sales order with multiple lines.  I want to ship several of the line items now, but keep the others open to ship later.  When I try to create a package for only the items I have on hand, the system won't allow me to pack zero of the other items. Short of deleting these items and entering them as a separate sales order, is there a way to do this?