Kenneth Isaacs appeals the sentence the district court 1 imposed after he pleaded guilty to conspiring to distribute and to possess with intent to distribute hydromorphone, in violation of 21 U.S.C. § 846. His counsel has moved to withdraw and filed a brief under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967). We reject counsel’s suggestion that appellant’s prior federal conviction for escape should not be considered a predicate offense for career-offender classification. See United States v. Nation, 243 F.3d 467, 472-73 (8th Cir. 2001) (holding that escape is categorically crime of violence). Having reviewed the record independently pursuant to Penson v. Ohio, 488 U.S. 75, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), we find no nonfrivolous issues for appeal. Accordingly, we affirm.