Kindle owners are being warned to update their e-readers today before it breaks forever.

Owners of the Kindle e-books have been warned to check their device for a critical update or else it will stop working by today (March 22).

The update applies to the 2012 Kindle Paperwhite and all previous versions, so if your Kindle is more than four years old, you'll have to update it quickly.

If users don't update before midnight today, they'll get an error message when they switch their devices on and will be unable to connect to the internet, preventing them from syncing their Kindles or downloading any new books.

If you received one of the e-readers for Christmas in 2013, or any time before, you need to make sure your device is updated.

It's not the end of the world if you don't manage to update it by the deadline. It just means you'll have to go through the comparatively arduous process of downloading the update from Amazon's website to a PC and installing it to the Kindle via USB.

On their website, the Amazon Help Team said: "Customers using an outdated software version on Kindle e-readers, or that have not connected wirelessly since October 5, 2015, require an important software update by March 22, 2016, in order to continue to download Kindle books and use Kindle services."

Amazon's Kindle was not the first e-reader on the market when it launched in 2007 but it proved innovative as it featured wireless connectivity.