In this direct criminal appeal, Timothy Gunn challenges the sentence the district court 1 imposed following his guilty plea to knowingly and intentionally conspiring to distribute at least 50 grams of a mixture containing cocaine base, in violation of 21 U.S.C. §§ 841(a)(1), (b)(1)(A), and 846. On appeal, counsel has moved to withdraw and has filed a brief under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967). Gunn has filed a pro se supplemental brief, arguing that the court should have held a hearing to evaluate his competency, that trial counsel was ineffective, and that the district court improperly denied his motion to withdraw his plea.

We conclude that the issues raised in the direct appeal fall within the scope of the appeal waiver that Gunn entered into knowingly and voluntarily and that enforcement of the waiver would not result in a miscarriage of justice. See United States v. Andis, 333 F.3d 886, 890-92 (8th *583 Cir. 2003) (en banc). 2

Finally, 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 that are not covered by the appeal waiver. Accordingly, we grant counsel leave to withdraw, and we dismiss the appeal.