Okla. Stat. tit. 12, § 1084
If a person who is either jointly or jointly and severally liable on a contract or obligation dies before an action is brought to enforce the contract or obligation and if the cause of action survives, the decedent's estate may be joined as a party to an action to enforce the contract or obligation.
Laws 1965, HB 820, c. 299, § 6.