Jaime Nevarez appeals from the sentence the District Court1 imposed after he pleaded guilty to a drug offense. His written plea agreement contained an appeal waiver. After consideration of both the brief filed under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), by Nevarez’s former appointed attorney and the supplemental brief later filed by a retained attorney, we conclude that the appeal waiver is enforceable as to all issues raised. See United States v. Andis, 333 F.3d 886, 889-92 (8th Cir.) (en banc) (discussing enforcement of appeal waivers), cert. denied, 540 U.S. 997, 124 S.Ct. 501, 157 L.Ed.2d 398 (2003). In addition, out of an abundance of caution, we independently reviewed the record, see Penson v. Ohio, 488 U.S. 75, 80, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), and we found no non-frivolous issue for appeal. Accordingly, we dismiss this appeal.