Matthew L. Hanson (Hanson) appeals the 144-month sentence the district court 1 imposed after granting the government’s post-judgment Federal Rule of Criminal Procedure 35(b) motion to reduce Hanson’s sentence based on substantial assistance. Hanson’s 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), arguing Hanson’s extensive cooperation warranted a 50% sentence reduction rather than the 20% reduction the district court applied. Counsel’s argument is unavailing. See United States v. Coppedge, 135 F.3d 598, 599 (8th Cir. 1998) (per curiam) (holding a challenge to the extent of a sentence reduction upon the government’s Rule 35(b) motion was unreviewable because the appeal was not based on any criteria listed in 18 U.S.C. § 3742(a)); United States v. Haskins, 479 F.3d 955, 957 (8th Cir. 2007) (per curiam) (concluding the court lacks jurisdiction to consider the reasonableness of a sentence following a Rule 35(b) reduction, because United States v. Booker, 543 U.S. 220, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005), did not expand § 3742(a) to include appellate review of discretionary sentencing reductions).

Having reviewed the record independently under Penson v. Ohio, 488 U.S. 75, 80, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), we find no nonfrivolous issues. We grant counsel’s motion to withdraw, and we affirm.