Appéllant challenges the denial of his postconviction motion filed pursuant to Florida Rule of Criminal Procedure 3.800(a). In his motion, Appellant argued that the trial court improperly authorized the Department of Corrections (“DOC”) to determine whether his gain-time should be forfeited after he was found in violation of his probation. He alleged that despite the fact that DOC did not have the authority to forfeit his gain-time based upon the date of his offense, it was nonetheless forfeited. The trial court summarily denied the mo-tion. We hereby, affirm, as this-claim is *956not cognizable pursuant to rule 3.800(a). See Dep’t of Corrections v. Mattress, 686 So.2d 740, 741 (Fla. 6th DCA 1997).
AFFIRMED.
LEWIS and THOMAS, JJ., concur; MAKAR, J., concurring with opinion.