Michigan Compiled Laws, Chapter 408. Labor § 408.423

Sec. 13. (1) An employer having employees subject to this act shall not discriminate between employees within an establishment on the basis of sex by paying wages to employees in the establishment at a rate less than the rate at which the employer pays wages to employees of the opposite sex for equal work on jobs, the performance of which requires equal skill, effort, and responsibility and that is performed under similar working conditions, except if the payment is made under 1 or more of the following:

(2) An employer that is paying a wage differential in violation of this section shall not reduce the wage rate of an employee to comply with this section.

(3) For purposes of administration and enforcement, any amount owing to an employee that has been withheld in violation of this section is considered unpaid minimum wages under this act.