Federal inmate William Hawkins appeals the district court’s 1 dismissal without prejudice of his 28 U.S.C. § 2241 petition. Upon careful review, see Mitchell v. U.S. Parole Comm’n, 538 F.3d 948, 951 (8th Cir. 2008) (per curiam) (de novo review), we conclude dismissal was proper, see Lopez-Lopez v. Sanders, 590 F.3d 905, 907 (8th Cir. 2010) (defendant who wishes to collaterally attack his conviction generally must do so through 28 U.S.C. § 2255); Langella v. Anderson, 612 F.3d 938, 940-41 (8th Cir. 2010) (decision whether to grant or deny parole is one Congress has committed to agency discretion and court has limited jurisdiction to review agency decisions).

Accordingly, we affirm. See 8th Cir. R. 47B.