On Tuesday, Apple launched iOS 16.2, a new version of the software that runs your iPhone and iPad. One of the most important features in the update is a tiny switch that makes data that you back up in iCloud a lot more secure.

The new feature, which Apple calls Advanced Data Protection, adds end-to-end encryption for backups of your Apple devices stored on iCloud. This means that only you can access the data those backups contain. If a hacker breaches Apple’s servers, for instance, they can’t get your stuff. If a law enforcement agency demands that Apple hand over your backup data, Apple can’t give it because not even Apple is able to look at anything in your backups. Advanced Data Protection is currently available in the US, and Apple users around the world will get it sometime in 2023.

The privacy community is cheering. The FBI, which has previously demanded personal data from Apple, is pissed.

Even if you’re not a privacy wonk or completely paranoid, you should turn on Advanced Data Protection, just because encrypting your personal data is good security hygiene.

In theory, doing this is as simple as flipping a switch in your iPhone’s or iPad’s settings. In practice, you do have to do a few things before that.

First, you should update all your Apple devices — not just your iPhone or iPad — to the latest version of their operating systems.

I’m a nerd, so I tried turning this feature on immediately after updating my iPhone to iOS 16.2, and this is what I got. It wanted me to update everything first. So do that.