After examining the briefs and the appellate record, this three-judge panel has determined unanimously that oral argument would not be of material assistance in the determination of this appeal. See Fed.R.App.P. 34(a); Tenth Circuit R. 10(e). This cause is therefore ordered submitted without oral argument.

This is a pro se appeal from an order of the United States District Court for the Northern District of Oklahoma, denying appellant Condit's motion, brought pursuant to 28 U.S.C. § 2255, to vacate, set aside or correct sentence. Appellant, presently incarcerated in the Federal Correctional Institution at Englewood, Colorado, argues that he was illegally sentenced upon revocation of his probation.

In 1974 appellant pled guilty in the District Court for the Northern District of Oklahoma to two counts of an indictment. The district court placed appellant on four years' probation for each count, pursuant to the Youth Corrections Act (YCA), 18 U.S.C. § 5010(a). Probation on the two counts was to run concurrently.

Approximately two years later appellant's probation was revoked and he was sentenced by the Oklahoma district court to eighteen months' imprisonment on Count I. For Count II, appellant was placed on two years' probation, this period to follow the term of imprisonment. Appellant was thus treated as an adult; no reference was made to the YCA.

Appellant served the eighteen-month sentence. Thereafter, supervision of appellant's probation for Count II was transferred to the United States District Court for the Eastern District of California. Approximately one year later nearly 41/2 years after the original four-year probationary periods were imposed appellant's probation was again revoked and the California court sentenced him as an adult to two years' imprisonment.

We must initially determine whether the Oklahoma district court properly assumed jurisdiction of this action. Jurisdiction lies only in "the court which imposed the sentence." 28 U.S.C. § 2255.1 See United States v. Hayman, 342 U.S. 205, 215, 72 S. Ct. 263, 270, 96 L. Ed. 232 (1952). Although appellant objects to the imprisonment ordered by the California court, his attacks are directed at the sentencing procedures of the Oklahoma district court. He argues that, once he was initially sentenced under the YCA, later adult sentencing was improper, and the errors in the Oklahoma court proceedings led directly to his present incarceration. Had the Oklahoma court not revoked appellant's YCA probationary status and substituted an adult sentence resulting in an extension of the probationary period the California court would no longer have had supervisory power over the appellant at the time probation was revoked and the present imprisonment could not have been ordered.2 Because "the California court had absolutely no connection with the proceedings presently being attacked," Record, vol. 2, at 12-13, the Oklahoma court asserted jurisdiction over the motion to vacate.

"A motion to vacate a sentence under § 2255 . . . will not lie unless the movant is in custody under such sentence." Blair v. United States, 349 F.2d 405, 405 (10th Cir. 1965). For jurisdiction to lie in the Oklahoma district court, the appellant must be both "in custody" and under a "sentence" of that court. "Custody" is not limited to physical confinement; it exists whenever conditions have been imposed "which significantly confine and restrain (the movant's) freedom." Jones v. Cunningham, 371 U.S. 236, 243, 83 S. Ct. 373, 377, 9 L. Ed. 2d 285 (1963). For purposes of the habeas corpus statutes, probation, like parole, constitutes "custody." See Hahn v. Burke, 430 F.2d 100, 102 (7th Cir. 1970).

The period of probation imposed by the Oklahoma district court has passed, but the appellant's present incarceration is based on, and his motion directly challenges, the allegedly erroneous sentencing procedures of that court. Since appellant's freedom has unquestionably been restrained by actions of the Oklahoma court, the "custody" requirement is satisfied for jurisdictional purposes.

The second requirement for jurisdiction in the Oklahoma court is that the order of probation must constitute a "sentence." In other contexts, this court has considered probation to be a category conceptually distinct from a sentence. See, e. g., Bartlett v. United States, 166 F.2d 928, 932 (10th Cir. 1948). However, we agree with the Seventh Circuit that, for purposes of 28 U.S.C. § 2255 and 18 U.S.C. § 3653 (the provision for revocation of probation and transfer of probationary supervision), probation is merely one form of sentence. Napoles v. United States, 536 F.2d 722 (7th Cir. 1976). See also Smith v. United States, 505 F.2d 893, 895 (5th Cir. 1974); Martin v. United States, 248 F.2d 554, 556 (8th Cir. 1957). In Napoles, on facts similar to those of the instant case, the court found jurisdiction to lie in the "court whose proceedings are being attacked." 536 F.2d at 726.

The practical justifications for the Napoles result are strong. The district court in the best position to evaluate the movant's claims retains jurisdiction.3 An appellate court's supervisory control over the district courts in its circuit remains undiminished. If other circuits were to become the situses for routine collateral attacks on the procedures followed by district courts of the Tenth Circuit, there would be a substantial danger of inconsistent, even contradictory, decisions. Finally, absent strong justification for a contrary result, we should follow the jurisdictional rules adopted by other circuits and not create an unnecessary dispute for ultimate Supreme Court resolution. If we declined to follow Napoles, we would place movants in these and other circuits in a strategic quandary.4

We believe therefore that the district court properly asserted jurisdiction over the attacks on its own proceedings. On the merits, the district court was clearly correct in determining that the adult sentence imposed upon revocation of YCA probation was within statutory limits. When YCA probation conditions are violated, the court "may impose any sentence which might originally have been imposed." 18 U.S.C. § 3653; Dunn v. United States, 561 F.2d 259, 261 (D.C.Cir.1977).

AFFIRMED.