Okla. Stat. tit. 22, § 22-741: Overt act in conspiracy

Upon a trial for conspiracy, in a case where an overt act is

necessary to constitute the offense, the defendant cannot be

convicted unless one or more overt acts be expressly alleged in the

indictment or information, nor unless one or more of the acts

alleged be proved; but any other overt act, not alleged in the

indictment may be given in evidence.