Last month, Google announced that consumers could start using their Android phones as physical security keys for two-factor authentication. The new option enables users to require login verification using a physical device but eliminates the need to use a separate dongle. Now in an update, Google announces to support this feature on iOS devices.

You can now use your Android phone to verify your sign-in on Apple iPads and iPhones. In an update about the feature, Google revealed that Android phones can now be used as physical security keys for iOS devices, too.

Security keys are an essential security step for users who are particularly at risk of advanced attacks. They’re designed to detect even the smartest and most resourceful attackers, like nation-state hackers. Instead of a security key that you keep on your key ring, newer Android devices have the technology built-in.

The Android phone built-in security key support was previously released for Windows 10 devices, macOS, and Chrome OS; it relied on Chrome browser to communicate with the user’s phone via Bluetooth. For the newly added iOS support, the security option uses the Google Smart Lock app.

The security key technology is also FIDO2 compliant, and for the Android security key to work, iPhone and iPad users need the Google Smart Lock app installed. For now, Google said the Android security key would be limited to sign-ins to Google accounts only.