Amazon Key, the service that lets the company’s couriers access your home to drop off parcels, works via a home security camera and a smart door lock. The service was introduced last October and runs in tandem with the Amazon Key app, which has been updated today on Android to include fingerprint authentication, as spotted by Android Police.

Amazon Key allows you to remotely lock / unlock your door and check delivery footage, so the extra layer of security is useful for people who might leave a secondary phone or tablet lying around the house. Reviewers have previously expressed concern that the app launches with automatic access to the camera, guest profiles, and the door lock — problems that should be mitigated with fingerprint authentication turned on.

The new fingerprint authentication feature arrives in the latest update on the Google Play store on Android. There’s no indication of when the feature will roll out on iOS.