Delta Air Lines is rolling out facial scanners at Minneapolis-St. Paul International Airport to give passengers the option of boarding planes with a glance at a camera rather than using a boarding pass.

The technology, being installed this week at 16 MSP gates, is aimed at simplifying the boarding process on international flights. With it, gate agents no longer need to compare passengers and their passport photos.

The facial scans mark the first use of biometric technology for boarding passengers at MSP. It will be available on Delta’s international flights from the airport next month, the airline said Wednesday.

Passengers have the option of using the facial-recognition technology or sticking with a traditional paper or digital boarding pass.

Delta installed and tested such biometric scanners at Concourse F in its home airport, Hartsfield-Jackson Atlanta International Airport, last year. In the months since, customer feedback was mostly positive, with 72% saying they preferred it to standard tickets, the airline said.

“We are already seeing improvements in satisfaction scores from customers moving through the airport in Atlanta,” Gil West, Delta’s chief operating officer, said in a statement.

“The expansion of facial recognition at boarding enables more customers to take advantage of this seamless, timesaving process,” he said.

In addition to the gates at MSP, Delta said it will install the technology at Atlanta’s Concourse E and at gates in Salt Lake City International Airport. Once this 49-gate expansion at the three airports is complete, Delta will have around 75 gates using facial scans for international boarding.

Delta previously tested a baggage-drop kiosk that uses facial scans at MSP. In Detroit, another hub for the airline, it is nearing completion of facial-scanning terminals that passengers can use for the entire process of checking in and boarding a plane, from curb to gate.

Airlines such as JetBlue and Lufthansa have installed facial-scanning devices for various parts of the passenger check-in process at other U.S. airports.

The carriers work with U.S. Customs and Border Protection, which match up facial scans with photos stored in the U.S. passport system. The agency is able to match more than 97% of faces with their existing database.

Customers with privacy concerns can tell a gate agent they would prefer not to have the facial scan. Delta said less than 2% of customers at Atlanta’s Concourse F decided not to use the process.

Some privacy advocates have expressed concerns that facial scans represent a new level of data for airlines and government to possess. If there were a breach of such data, said Bob Mann, a Port Washington, N.Y.-based airline consultant, it raises the prospect of greater detail being sold by nefarious actors on the black market. “It’s very different from an airline having your birth date and passport number,” Mann said.

The process sharply cuts down the time spent boarding passengers, airlines find. For a widebody aircraft that holds about 270 people, boarding time can be shaved by nine minutes, Delta said, or about two seconds per passenger.