Mich. Comp. Laws § 769.11a: Void sentence; trial judge to credit time served.

Sec. 11a.

Whenever any person has been heretofore or hereafter convicted of any crime within this state and has served any time upon a void sentence, the trial court, in imposing sentence upon conviction or acceptance of a plea of guilty based upon facts arising out of the earlier void conviction, shall in imposing the sentence specifically grant or allow the defendant credit against and by reduction of the statutory maximum by the time already served by such defendant on the sentence imposed for the prior erroneous conviction. Failure of the corrections commission to carry out the terms of said sentence shall be cause for the issuance of a writ of habeas corpus to have the prisoner brought before the court for the taking of such further action as the court may again determine.