OPINION

Michael Gindraw appeals his conviction and sentence imposed by the district court following his guilty plea to possession of marijuana with intent to distribute pursuant to 21 U.S.C. § 841(a)(1) (2000). Counsel has filed a brief in accordance with Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967). Additionally, Gindraw has filed a pro se supplemental brief and a motion for appointment of new counsel. Finding no reversible error, we affirm.

On appeal, Gindraw contends his Fed. R.Crim.P. 11 plea hearing was inadequate. In light of the district court’s thorough plea colloquy, we find this argument to be without merit.

Gindraw also contends the district court erred in calculating his sentencing guidelines range. We find no error in the district court’s calculations. Gindraw further contests the extent of the district court’s downward departure and the choice of a sentence within the guidelines range. However, neither the extent of the district court’s departure nor the district court’s imposition of a sentence within a properly calculated range are reviewable by this court. See United States v. Hill, 70 F.3d 321, 324-25 (4th Cir. 1995); United States v. Porter, 909 F.2d 789, 794 (4th Cir. 1990).

Gindraw next contends the district court failed to address his objections to the presentencing report. A review of the record shows the district court did, in fact, resolve Gindraw’s objections. Gindraw also contends he was detained too long prior to his arraignment. However, by pleading guilty, Gindraw has waived any claims with respect to antecedent non-jurisdictional defects. See United States v. Willis, 992 F.2d 489, 490 (4th Cir. 1993); Tollett v. Henderson, 411 U.S. 258, 267, 93 S.Ct. 1602, 36 L.Ed.2d 235 (1973).

Pursuant to Anders, we have reviewed the record and find no error. Accordingly, we affirm Gindraw’s sentence and conviction. We deny Gindraw’s motion for appointment of new counsel. This court requires that counsel inform his client, in writing, of his right to petition the Supreme Court of the United States for further review. If the client requests that a petition be filed, but counsel believes such a petition would be frivolous, then counsel may move in this court for leave to with *435 draw from representation. Counsel’s motion must state that a copy thereof was served on the client. 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.