One of Europe’s largest airlines is saying “auf wiedersehen” to Apple AirTags on checked luggage.

Lufthansa, Germany’s main airline, tweeted Saturday that the company is banning “activated AirTags” from luggage because the devices “are classified as dangerous and need to be turned off” during flights.

Apple’s AirTags are a quarter-sized Bluetooth tracker that can be used to track personal items, such as car keys or bags, using an iPhone’s “Find My” app. Travelers have begun to attach the tracking devices to their luggage to track where their bags are, in the event an airline loses it.

A spokesperson for Lufthansa told the German news outlet Watson that travelers would need to remove the battery from AirTags—therefore making them unable to be tracked—if the device was attached to checked luggage.

“Baggage trackers belong to the category of portable electronic devices and are therefore subject to the dangerous goods regulations for carriage in airplanes issued by the International Civil Aviation Organization,” the spokesperson said.

In a tweet Sunday, Lufthansa explained that due to the AirTags’ Bluetooth transmission function, the trackers must be deactivated during flight if they are placed in checked luggage.

As for flyers in the United States, the Transportation Security Administration confirmed Friday that Bluetooth tracking devices, such as AirTags, are allowed on both carry-ons and checked luggage.

Although the Federal Communications Commission still bans the use of cellphones on flights to protect against radio interference to grounded cellphone networks, the Federal Aviation Administration allows passengers to use short-range Bluetooth devices and other personal electronics, so long as they remain on airplane mode.

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