Apple’s new TV calibration feature, which uses the iPhone’s front-facing sensors to sense and tweak the output of the Apple TV, works with the company’s older streaming boxes, 9to5Mac reports. The new feature will arrive with tvOS 14.5, which is due to release “early next week” for the 2017 Apple TV 4K and 2015 Apple TV HD. Apple says viewers will see “much more accurate colors and improved contrast” after calibration.

The calibration feature was announced alongside the new Apple TV 4K. It works by having you hold up the front of your iPhone to your TV, so it can sense how the screen is outputting different colors. If the phone’s light sensor sees that color is being outputted inaccurately, the Apple TV can adjust its output to compensate. The process only covers the Apple TV’s content, and won’t affect the TV’s built in apps or other devices it has plugged in.

According to 9to5Mac, Apple TV HD and 4K owners can access the calibration feature via the Video and Audio section in the Settings app. As well as requiring an Apple TV updated to tvOS 14.5, the feature also requires Face ID-equipped iPhone running iOS 14.5. Both FlatPanelsHD and CNET note that the feature doesn’t work on TVs with Dolby Vision enabled after testing it with older Apple TVs running the latest tvOS 14.5 beta build, though it’s not immediately clear why this is.

Between this and the news that Apple’s redesigned Siri Remote will also work with older Apple TVs, Apple is making it pretty easy for existing Apple TV owners to hold off on upgrading.