If you have an Amazon Kindle e-reader model from 2012 or earlier, you'll need to update the software by Tuesday to keep it working.

An "important software update" needs to be installed on fifth generation and older Kindle models by March 22, in order for users to download Kindle books or use Kindle services after that date, Amazon said on its Kindle Help Community website on March 3.

If the software is not updated, starting Tuesday, when users try to use their e-reader, they'll get a message saying the Kindle is "unable to connect."

At the moment, the update can be done using a wireless or Wi-Fi connection. But software updates after March 22 will have to be done manually.

Kindle sixth and seventh generation models do not need to be updated.