Former U.S. Attorney General is weighing in on the side of Uber in the ride-share service’s effort to avoid fingerprint checks for drivers who want to make pickups at Hartsfield-Jackson International Airport.

Holder wrote a letter to Atlanta Mayor Kasim Reed, whose administration is considering regulations for airport pick-ups, in which he said a fingerprint requirement might discriminate against minorities.

“Requiring fingerprint-based background checks for non-law enforcement purposes can have a discriminatory impact on communities of color,” he wrote.

The city-owned airport earlier this year proposed to legalize airport ride-share pickups and require fingerprint-based background checks for Uber X and Lyft drivers. Taxi and limo drivers who work the airport have long been fingerprinted and say they want a level playing field.

Uber and Lyft object to the proposed requirement, saying they do their own background checks, which do not require fingerprints. They say fingerprint checks are cumbersome and would hurt recruitment of new drivers.

The city is currently revising the airport proposal but has not said how it will change.

Holder’s reasoning, also voiced by Uber: FBI records may lack information about the final outcome of some cases, and may not indicate if someone arrested was charged or convicted, so a fingerprint-based check “can prevent people from getting a job even if they were never found guilty of a crime.”

That “disproportionately disadvantages people who have been arrested,” which “can have a discriminatory impact on communities of color,” Holder wrote.

Reed’s office and the airport acknowledged receiving the letter but declined to comment on it. Backers of a fingerprint rule say Holder’s concern is misplaced because generally in Georgia only a conviction would rule out an applicant.

Holder, who left office in April 2015, works for law firm Covington & Burling, which has a relationship with Uber.

Holder has written recent similar letters to officials in New Jersey and Chicago amid ride-share debates there.