Some Amazon account holders were required to change their passwords this week after the online retailer found that the information could have been compromised.

Technology website ZDNet first reported the news Tuesday, noting Amazon wrote in an email addressed to affected users that there was “no reason” to believe the information had been leaked.

ZDNet reported the email said Amazon forced the password change as a purely precautionary measure after learning that the passwords might have been improperly stored or transmitted, which could have allowed a third party to access it.

It’s not clear how many people were asked to reset their passwords and Amazon corrected the issue.

The company has recently taken steps to improve cyber security.

Last week, it began allowing customers to require two-factor authentication to access their account. That requires users to not only successfully enter their password to log in to the website, but also a second group of characters that is typically sent to a user’s mobile phone.