Problems with a popular accessory for iPad Pro tablets has prompted Apple to extend the free warranty for it.
The extended warranty is for Apple’s Smart Keyboard device that people can connect to their iPad Pro tablets to use to type instead of using the touch screen, according to a report this week by tech publication 9to5Mac. Under the warranty, people who bought a Smart Keyboard for either the 12.9- and 9.7-inch versions of the iPad Pro will be entitled to free repairs for up to three years instead of the usual one year.
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Apple sent an internal memo to its retail store employees and partner service providers on Friday that said it discovered “functional issues” with the keyboards that need to be fixed, the report said. Some of the problems with the keyboard include sticky keys that cause repeat typing, connection errors, and unresponsive keys.
Apple aapl currently offers a one-year warranty for all of its various devices and accessories. The new warranty extends the existing warranty for another two years to cover the Smart Keyboards.
Apple debuted its iPad Pro in 2015 as a more business-friendly tablet that, with the help of a detachable keyboard, makes it more suitable for the workplace—much like Microsoft’s msft Surface tablet.
The 9.7-inch version of the Smart Keyboard sells for $150 while the larger model costs $170.
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Fortune contacted to Apple for more information including how many keyboards were affected, and we’ll update this story if it responds.