Apple on Friday announced a new program that invites millions of iPhone users across 37 different countries to swap out their iPhone chargers, which may be faulty. According to Apple’s website, the company has determined that one of its iPhone charger models can potentially overheat and pose a safety risk. Apple says overheating only occurs in rare cases, but it apparently decided to play it safe and offer users the opportunity to swap affected chargers out for newer models.

Of note, chargers that ship with newer iPhone models are not affected by this potential issue. According to Apple, only model A1300 chargers that shipped with the iPhone 3GS, iPhone 4 and iPhone 4S pose a potential risk.

“Apple has voluntarily introduced a program for customers to exchange the Apple 5W European USB Power Adapter which came with iPhone 3GS, iPhone 4 and iPhone 4S models through September 2012, because in rare cases the adapter may overheat and pose a safety risk,” the company said in a statement.

More details on the exchange program can be found on Apple’s website, which is linked below in our source section.