Okla. Stat. tit. 15, § 217
Every contract by which any one is restrained from exercising a lawful profession, trade or business of any kind, otherwise than as provided by Sections 218 and 219 of this title, or otherwise than as provided by Section 2 of this act, is to that extent void.
R.L. 1910, § 978; Amended by Laws 1989, SB 257, c. 359, § 1, emerg. eff. June 3, 1989; Amended by Laws 2001, SB 662, c. 406, § 3, emerg. eff. June 4, 2001 (superseded document available).