On Monday, the Supreme Court heard oral arguments in Southwest Airlines’s appeal to reverse a 7th Circuit ruling that held its workers suing the airline for overtime pay were exempt from the Federal Arbitration Act (FAA). The case, Southwest Airlines Co v. Saxon, is set to settle a circuit court split on how attenuated baggage supervisors are from interstate commerce.

The FAA requires the enforcement of employee arbitration agreements but exempts “seamen, railroad employees, or any other class of workers engaged in foreign or interstate commerce.” Southwest Airlines workers claim an exemption under this provision of the FAA as they “engage in interstate commerce” in their critical role of loading and unloading plane cargo. Southwest, on the other hand, argued that the exemption only applied to workers directly involved in the actual operation of the planes. In a parallel case involving Lufthansa Airlines, the 5th Circuit held the workers not exempt from the FAA. While a number of Justices appeared skeptical of Southwest’s reasoning, other members of the Court, including Justice Gorsuch, expressed discomfort with the employees’ definition of “engaging in interstate commerce” as opening the definition too broadly to encompass a myriad of workers.