Amazon has issued a new update to its Kindle iOS app and users must install the latest version before upgrading to iOS 7 or risk losing their Kindle libraries.

Amazon released the Kindle 3.9.2 update on Monday. In the update, the company explains:

This is a fix for a Kindle issue with the upcoming iOS7 OS upgrade that may cause customers to have to re-register and re-download books from Amazon. Please download and install – this is a required update before upgrading to iOS7

Apple’s iOS 7 launches on September 18th, so users have about a week to update their Kindle apps before the new operating system is available to download.