Okla. Stat. tit. 18, § 18-817: Prior corporation

This act shall not apply to any persons within this state who

prior to the passage of this act were permitted to organize a

corporation and perform professional services by the means of such

corporation, and this act shall not apply to any corporation

organized by such persons prior to the passage of this act;

provided, however, any such persons or any such corporation may

bring themselves and such corporation within the provisions of this

act by amending the certificate of incorporation in such a manner so

as to be consistent with all of the provisions of this act and by

affirmatively stating in the amended certificate of incorporation

that the shareholders have elected to bring the corporation within

the provisions of this act.