Okla. Stat. tit. 36, § 4108

In group annuity contracts there shall be a provision, with an appropriate reference thereto in the certificate, for the equitable adjustment of the benefits payable under the contract or of the stipulated payments thereunder, if it be found that the sex, age, service, salary or any other fact determining the amount of any stipulated payment or the amount or date or dates of payment of any benefit with respect to any annuitant covered thereby has been misstated. Laws 1957, p. 385, § 4108.