Appellant pleaded guilty to a violation of 18 U.S.C. § 2312. He seeks relief from the sentence imposed and asserts mental incompetence at the time of the guilty plea. The trial court treated his petition for coram nobis as an application under 28 U.S.C. § 2255 and denied it without a hearing.

A claim of mental incompetence at the time of a guilty plea may be raised under § 2255 and, when raised, may not be disposed of without a hearing. See Ellison v. United States, 10 Cir., 324 F.2d 710, decided today. As in Ellison we direct the attention of the trial court to the admonitions appearing in Machibroda v. United States, 368 U.S. 487, 495-496, 82 S.Ct. 510, 7 L.Ed.2d 473, and in Sanders v. United States, 373 U.S. 1, 20-23, 83 S.Ct. 1068, 10 L.Ed.2d 148.

Reversed and remanded for further proceedings in conformity with the views here expressed.