Okla. Stat. tit. 15, § 213
Except as expressly provided in Section 215 of this title, penalties imposed by contract for any non-performance thereof, are void. But this section does not render void such bonds or obligations, penal in form, as have heretofore been commonly used; it merely rejects and avoids the penal clauses.
R.L. 1910, § 974; Amended by Laws 1985, SB 299, c. 107, § 1, emerg. eff. May 28, 1985.