Apple has launched a free repair program for iPhone 6s and 6s Plus users experiencing unexpected shutdowns on their device. Under the new program Apple will replace the battery on devices experiencing the fault, though if the device has a cracked screen or other damages then customers will have to pay for those fixes before the battery can be replaced.

The repair program follows the recent announcement that customers affected by the iPhone 6 Plus “Touch Disease” can get their screens replaced for a reduced rate of $149.

As for this fault, Apple says only a small subset of users will be affected. The fault is only present on some devices manufactured in September and October of 2015. The device’s serial number will dictate whether a device is eligible. If you’re experiencing the fault, serial numbers and replacements can be checked and made by Apple in one of their retail stores (make an appointment here) or via an Apple Authorized Service Provider (find one here).

If customers have previously paid for a new battery on an eligible device then they can apply for a refund from Apple by contacting them here.

For more information visit the iPhone 6s Program for Unexpected Shutdown Issues support page.