Apple will add its processor throttling feature to the iPhone XS and XR next week with the upcoming iOS 13.1 update. The feature, which was controversial when first discovered in 2017, limits some iPhones’ performance to prevent random shutdowns due to aging batteries. The feature is only supposed to be active when a phone has an older battery, but those affected have previously complained about noticeable slowdowns of their devices when it happens.

The feature was discovered when iPhone owners noticed that older phones would speed up after a battery replacement. Apple eventually became more transparent about the feature, detailing how it worked and temporarily offering discounted battery replacements as a mea culpa. It later updated iOS so that, even if your phone is at risk of random shutdowns, you can turn off the processor throttling feature to regain full performance. The feature will only be activated after the iPhone detects an unexpected shutdown because of battery issues.

Apple has said that newer iPhone models have more advanced power-monitoring hardware, which should reduce the impact of throttling. That advanced hardware was present on the iPhone 8 and X, which got the processor throttling feature in an update this time last year, as well as the XR and XS.

While Apple hasn’t said whether this feature will eventually come to the new iPhone 11 models, 9to5Mac spotted a new support page in which Apple details a “more advanced” battery and power management system than on older phones. Apple says the feature is “automatic” and “always-on,” suggesting that some version of the feature may be around from the start.

All battery-powered devices are going to run into issues as they age, as their battery weakens and is no longer able to sustain peak outputs. That can lead to slowdowns and occasional shutdowns, often without any clarity to the user about what’s happening. For better or worse, though, Apple seems to be the only smartphone maker actively limiting its phones’ performance as they age. In 2017, Samsung, LG, HTC, and Motorola all said they don’t employ the same practice.

iOS 13.1 will be released on September 24th. It includes some new features and hopefully some bug fixes that’ll address issues early adopters of iOS 13 are having.