Lewis Bolden, previously convicted of a felony drug offense, pled guilty to conspiring to distribute and possess with intent to distribute 100 grams or more of a mixture or substance containing a detectable amount of heroin in violation of 21 U.S.C. §§ 841(a)(1), (b)(1)(B), 846, and 851. The district court 1 departed downward from the calculated Guidelines range and sentenced Bolden to 200 months in prison and eight years of supervised release. Bolden appeals his sentence, challenging the extent of the downward departure and arguing that the sentence is unreasonable. His counsel has filed a brief pursuant to Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), and moved to withdraw.

This court cannot review the extent of the departure, given that Bolden does not allege that the district court was motivated by an unconstitutional motive in arriving at its downward-departure decision. See United States v. Robinson, 536 F.3d 874, 878 (8th Cir. 2008). Further, upon careful review as to the reasonableness of the sentence, this court finds that the sentence is not unreasonable, see Gall v. United States, 552 U.S. 38, 51, 128 S.Ct. 586, 169 L.Ed.2d 445 (2007) (procedure for reviewing sentence); see also United States v. Berni, 439 F.3d 990, 992-93 (8th Cir. 2006) (per curiam) (reviewing sentence involving downward departure for reasonableness using abuse-of-discretion standard). An independent review of the record under Penson v. Ohio, 488 U.S. 75, 80, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), reveals no nonfrivolous issues.

*526 The judgment of the district court is affirmed, and counsel’s motion to withdraw is granted.