During the height of the holiday shopping season, Amazon warned some users that the browser extension Honey could be a “security risk.”

PayPal paid $4 billion for the start-up, which has worked with Amazon since it was founded in 2012. This appears to be Amazon’s first public warning about Honey’s security concerns.

PayPal was once a part of Amazon competitor eBay, and Amazon does not accept PayPal as an option in check-out. Amazon also has a competing discount plug-in.