WhatsApp users are beginning to see an option for two-factor authentication their account settings folder. According to Android Police, the feature is live in the most recent betas of the app (2.16.341 and above), and has also been spotted in the Windows Phone beta. Once activated, the app will prompt a user for a static six-digit passcode every time a new phone is registered to the account.

The new code might seem inconvenient, but it provides a crucial line of defense against criminals who might try to clone your phone, convincing a carrier to assign your phone number to their new mobile device. Without two-factor protections, all that’s required to register a WhatsApp account on a new device is a confirmation SMS message — but since that message is sent to all devices registered under your phone number, it’s trivial to break if the attacker has cloned your device.

The feature has been rumored for some time, but this the first time a functional version has been available to users. And while it’s still only in beta versions of the app, it’s only a matter of time before it makes the leap to the official release.