DETROIT—Stellantis is cutting one shift at its assembly plant here, where the Jeep Grand Cherokee is built, not because of a lack of demand but rather due to emissions regulations in California.

The manufacturer has revealed that the Mack site will drop from three shifts to two shifts “temporarily.” It is not yet known how many fewer Grand Cherokee models will be produced due to the change nor how the change will impact the 4,600 employees who work at the site.

Stellantis said the production change was being made “in part because of the need to manage sales of the vehicles they produce to comply with California emissions regulations that are measured on a state-by-state basis.”

For more than six months, the company has been limiting the shipment of gasoline-powered vehicles to dealers in states that have adopted California’s strict emissions rules to comply with these stricter regulations. Stellantis has also “at times” limited the sale of plug-in EVs to states adopting California rules and only shipped vehicles ordered directly by customers to some other states.

This isn’t the only production change that Stellantis is making. The company’s assembly plant in Toledo, OH, which makes the Jeep Wrangler, will also move from an alternative work schedule to a two-shift operation. This change will lead to job cuts, and the company has warned more than 3,600 employees of possible job impacts.