Guillermo Ruiz, a federal prisoner, appeals the district court’s order accepting the recommendation of the magistrate judge and denying relief on his 28 U.S.C. § 2241 (2000) petition. The district court referred this case to a magistrate judge pursuant to 28 U.S.C. § 636(b)(1)(B) (2000). The magistrate judge recommended that relief be denied and advised Ruiz that failure to timely file specific objections to this recommendation could waive appellate review of a district court order based upon the recommendation.

The timely filing of specific objections to a magistrate judge’s recommendation is *259 necessary to preserve appellate review of the substance of that recommendation when the parties have been warned of the consequences of noncompliance. Wright v. Collins, 766 F.2d 841, 845-46 (4th Cir. 1985); see also Thomas v. Arn, 474 U.S. 140, 106 S.Ct. 466, 88 L.Ed.2d 485 (1985). Ruiz has waived appellate review of the magistrate judge’s conclusion regarding whether his claims were cognizable under § 2241 by failing to lodge that specific objection to the magistrate judge’s recommendation after receiving proper notice of the consequences of the failure to object.

Accordingly, although we grant leave to proceed in forma pauperis, we affirm the district court’s order. We dispense with oral argument because the facts and legal contentions are adequately presented in the materials before the court and argument would not aid the decisional process.

AFFIRMED.