George Williams appeals from Judge Parker’s order dismissing his pro se habe-as corpus petition for lack of subject matter jurisdiction. Appellant’s habeas petition challenged a prior state conviction, for which the sentence had already expired. The district court determined that there was no jurisdiction because appellant was not “in custody” under the challenged conviction, as required by Maleng v. Cook, 490 U.S. 488, 491-92, 109 S.Ct. 1923, 104 L.Ed.2d 540 (1989).

On January 8, 1999, we granted appellant’s motion for a certificate of appealability. On appeal, Williams argues that because his current sentence was enhanced by his allegedly unconstitutional prior conviction, there is subject matter jurisdiction. The district court correctly observed that a petitioner is not deemed “ ‘in custody’ under a conviction after the sentence imposed for it has fully expired.” Maleng, 490 U.S. at 492-93, 109 S.Ct. 1923; see also 28 U.S.C. §§ 2241(c), 2254(a). However, “the ‘in custody’ requirement for federal habeas jurisdiction” is satisfied when a pro se petition, liberally construed, “can be read as asserting a challenge to [a current] sentence! ], as enhanced by [an] allegedly invalid prior conviction,” Maleng, 490 U.S. at 493-94, 109 S.Ct. 1923. Appellant is currently incarcerated in New York under a state manslaughter conviction entered pursuant to a plea agreement, and appellee concedes that appellant’s allegedly invalid prior conviction “form[ed] the legal basis for the current enhanced sentence.” Because appellant’s petition makes sense only as “an attempt to end or reduce his current incarceration,” Malik v. Brennan, No. 93 Civ. 786(DC), 1995 WL 510047, at *2 (S.D.N.Y. Aug.29, 1995), we remand to the district court to permit appellant to amend his petition to challenge explicitly his current sentence’s allegedly illegal enhancement, see Taylor v. Armontrout, 877 F.2d 726, 727 (8th Cir. 1989).

We do not address the merits of appellant’s petition.