Apple moved to address many of the privacy concerns raised after the release of AirTags. The item trackers launched with anti-stalking features, but a new firmware update is tightening them up further.

AirTags will start more quickly warning people if they’re being used to follow someone. And an Android app that can detect these trackers is in development.

AirTag doubles down on preventing stalking

The AirTag changes Apple revealed to Cnet on Thursday primarily benefit non-iPhone users. Previously, the accessory could be used to stalk an Android user very easily.

At launch, AirTag included a timer that, after three days, would set off an audible alarm to alert people that the tracker was nearby and out of range of its owner. That’s been changed to a random interval between 8 hours and 24 hours.

While making AirTag stalking harder, the new alarm interval is not a benefit for people who put a tracker on something they are afraid will be stolen. For example, if someone hides a tracker on their bike, they’ll need to be sure they’re never away from the bike  for more than 8 hours to prevent the alarm from going off.

Beyond the audible signal, a way for Android users to be sure they aren’t being followed by one of Apple’s trackers is in development. iPhone users already get a warning if someone else’s AirTag is following them around. An Android app that can do this will be out later this year.