The Apple Watch Series 4’s long-promised electrocardiogram (EKG) feature may finally get support in the upcoming watchOS 5.1.2 update, according to an Apple Store training document obtained by MacRumors.

The feature will let the wearable device take EKG measurements using electrodes built into the back of the Watch and the digital crown, improving the Apple Watch’s ability to measure and monitor users’ hearts. Apple has received Type II FDA clearance for the Apple Watch in the US, which, as Angela Chen explains, isn’t quite the same thing as full Type III FDA approval.

According to the training document, the EKG features will only be available in regions where the Apple Watch has been cleared for use, which seems to only be the US at the initial launch. That said, it’s hard to imagine that Apple isn’t already working to get medical approval for other countries.

The updated watchOS 5.1.2 is in beta testing for developers, but there’s no word yet as to when the final version will be released.