Illinois regulations that require staffing firms to provide temporary workers equal pay compared to directly employed workers was signed into law by Illinois Gov. JB Pritzker on Friday.

The regulations affect only industrial contingent workers, and the provision related to equal pay for contingent workers is similar to a New Jersey law that took effect Aug. 5. However, the Illinois law’s equal pay regulations take effect only after a contingent worker has been on a worksite for 90 days, which was added after lobbying by the American Staffing Association.

In the Illinois law, the official wording that calls for equal pay reads in part:

“Equal pay for equal work. A day or temporary laborer who is assigned to work at a third-party client for more than 90 calendar days shall be paid not less than the rate of pay and equivalent benefits as the lowest paid directly hired employee of the third-party client with the same level of seniority at the company and performing the same or substantially similar work on jobs the performance of which requires substantially similar skill, effort, and responsibility, and that are performed under similar working conditions.”

Legislation sponsor Rep. Edgard Gonzalez, D-Chicago, said in a Chicago Workers Collaborative press release that the regulations will mean an average of $4 more per hour for thousands of contingent workers in his district.