MEMORANDUM **

Demond Maurice Mimms, a California state prisoner, appeals pro se from the district court’s order dismissing his 42 U.S.C. § 1983 action alleging that defendants sentenced him to an unconstitutional prison term. We have jurisdiction pursuant to 28 U.S.C. § 1291. We review de novo, Barren v. Harrington, 152 F.3d 1193, 1194 (9th Cir. 1998) (order), and we affirm.

The district court properly dismissed Mimms’s action because his challenge concerns the legality of his detention, and a *166judgment in his favor would necessarily imply the invalidity of his continued confinement. See Heck v. Humphrey, 512 U.S. 477, 487, 114 S.Ct. 2364, 129 L.Ed.2d 383 (1994).

AFFIRMED.