In a blink-and-miss-it move, the online retail giant quietly reduced its free shipping minimum rate to $35. The change was picked up and reported by a number of news outlets over the weekend, and was spotted by Fortune as well during the online checkout process.

Amazon (AMZN) confirmed the change on its shipping guidelines and options page, designating which items and regions for delivery are eligible for free shipping.

Amazon’s free shipping rate, arguably one of the promotions on the site that has been the most popular and vaulted it to its e-commerce throne in years past, has gone up and down over the years. The free shipping minimum has been as low as $25 in the past and was most recently as high as $49.

The rate has gone up in recent years as Amazon continues to nudge consumers to subscribing to its Prime subscription service, which includes not only free two-day shipping but also access to its digital library of movies, books, and more. Some third-party retailers on Amazon already offer free shipping on select goods without a minimum, and even some of Amazon’s own products (such as its original book business) already have a lower free shipping bar.

However, Amazon’s decision to quietly roll back its free shipping minimum to $35 without much fanfare has incited some followers to speculate if the tech company is feeling the pressure from other major retailers (notably Walmart) with lower free shipping requirements.