Why does my mortgage company want me to sign the check over to them?

I recently filed a claim with my homeowners insurance carrier for hail damage to my roof. It has been determined that the roof needs to be replaced, and the insurance carrier sent me a check for about half of the amount. This is a usual practice, and the balance will be paid upon completion of the job.

The check was made payable to myself and my wife (mortgage holders) and the mortgage company. When I contacted the morgtage company to get the check endorsed, I was instructed to endorse the check and submit it to the mortgage company, who will in turn re-disburse the funds. Is this a standard procedure, or is there something fishy going on here?