LANSING, Mich. (AP) — The Michigan State Police plans to change how troopers record the race of drivers during traffic stops following a complaint from the American Civil Liberties Union of Michigan.

MLive.com reports that the agency is making the change so officers’ electronic daily records no longer default to “unknown” for the driver’s race, attempting to get more accurate data.

The ACLU had questioned a policy encouraging troopers to make an amount of traffic stops equivalent to 70 percent of a post average and raised questions about how state police would review a trooper’s activity to determine if a traffic stop was improper if a complaint was made.

Starting Jan. 1, Mlive.com says the troopers will be required to identify people using one of five categories defined by the U.S. Census.