how to prevent Overdelivery against as Stock Transport Order?

Hi,

I have a problem where my user is able to do Overdelivery against as Stock Transport Order, STO is raised from one Plant to another within the same company code.

The process is a) STO b) Delivery Process against an STO c) GR

PS: By doing "B" error message with delievry stopped at the delivery item category for the STO, it is not able to stop.

Please advise.

Regards