In Clevenger v. Burgess, 31 S.W.2d 675 (Tex. Civ. App.--Beaumont 1930, writ ref'd), the nonsubscribing employer had paid his injured employee an extra dollar per day over his regular wages, which the employer contended was sufficient to allow the employee to insure himself against work-related injuries. The employer claimed that, by accepting the additional pay, the employee assumed the risks ordinarily incident to the work he was doing and the employer had the right to plead all defenses available under the common law. Clevenger, 31 S.W.2d at 676. The record contained no evidence of the waiver agreement, if in fact there was one, because neither party disputed that any such agreement was inadmissible under the version of the Act then in effect. Rather, the employer claimed the Workers' Compensation Act unduly interfered with his right to contract and was therefore unconstitutional. The Court upheld the Act's constitutionality, stating that "the constitutional right to contract is not infringed by forbidding contracts whereby employers relieve themselves of liability imposed by statute." Clevenger, 31 S.W.2d at 678. Once again, Clevenger involved a unilateral action by the employer that appears to have been a condition of employment, and did not involve an employee's voluntary election of employer-provided benefits. Id.