Apple Watch could soon add sleep-tracking tech that makes it an even more capable health monitor.

Apple has been testing the new sleep-tracking technology at secret sites around Cupertino, a new report claims. And if it lives up to its promise, it could ship as part of the Apple Watch by 2020.

The FCC granted its approval for Apple to make a “Sleep Monitor.” This is almost certainly an improved version of the Beddit, a product the company acquired last year.

It will apparently join Apple’s growing lineup of health-tracking products.

This week on The CultCast: It’s official — the Worldwide Developers Conference keynote takes place June 5. Don’t miss our WWDC 2017 hardware expectations! Plus: Apple quietly acquires one of the world’s best sleep-tracking technologies; why Amazon’s Prime Video app may finally be coming to your Apple TV; our first impressions of the Amazon Echo Show, and the features we hope Apple steals from it; and stick around for a very weird, very tribal “What We’re Into,” the segment where we reveal all the non-tech stuff we’re currently digging.

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Apple has acquired acquired a sleep-tracking app called Beddit, suggesting that tracking users’ hours of shut-eye could be incorporated into a future Apple Watch or iPhone.

Financial terms of the acquisition haven’t been disclosed, although the buyout is confirmed by Beddit in the small print on its webpage.

The last thing I want to do as I stumble into my bed through a bourbon-soaked fog is to set up my sleep-tracking device. It’s nice to have an app tell me how fitful is my kip, but the pre-sleep perambulations are a pain: you have to slip your Fitbit into a wrist strap, or plug in your iPhone and launch the sleep-tracking app.

Beddit takes a different approach. It’s a strap that stays permanently wrapped around your mattress, ready to record your snoozes.