Alphabet Inc.’s (GOOG) Google has started preventing users of Inc. (AMZN) devices from accessing YouTube and plans to block the popular video streaming service altogether starting on the first day of 2018.

In a statement to Variety, which first spotted the move by Google on Tuesday, the online search giant said it pulled YouTube from Amazon-made Echo and Fire TV devices because Amazon isn’t interested in reaching a business deal with Google over carrying its other products. “We’ve been trying to reach an agreement with Amazon to give consumers access to each other’s products and services. But Amazon doesn’t carry Google products like Chromecast and Google Home, doesn’t make Prime Video available for Google Cast users, and last month stopped selling some of Nest’s latest products. Given this lack of reciprocity, we are no longer supporting YouTube on Echo Show and FireTV. We hope we can reach an agreement to resolve these issues soon,” a Google spokesperson told Variety. (See also: Amazon's Alexa Will Approach 71% of Smart Speaker Market: eMarketer.)

Blocking and Bickering

Not surprisingly, Amazon quickly fired back with its own statement to Variety saying the Echo Show and Fire TV display a standard web view of and send customers directly to the website. “Google is setting a disappointing precedent by selectively blocking customer access to an open website. We hope to resolve this with Google as soon as possible.” (See more: Amazon, Google Feud Over YouTube Removal From Echo Show.)

This isn’t the first time in recent weeks that the two have had a public fight over YouTube on Amazon devices. In late September, Google pulled YouTube from Echo Show devices without any warning, making the same argument. The companies blamed each other in that incident but a source familiar with YouTube’s thinking told Variety that this time around Amazon violated YouTube’s terms of service because it layered voice control over an app that wasn’t made to interact with voices. Still, even with some technical issues involved in the latest dispute, it's much more likely to have to do with simmering resentments over which Google products Amazon sells and which it doesn’t. In late 2015, Amazon stopped selling Google’s Chromecast streaming adapter and never really sold the Home voice-activated speaker, hurting sales of both products. According to Variety, Amazon also kicked some of Google’s Nest products off its e-commerce site after Google blocked YouTube on the Echo Show in September. By blocking YouTube, which is hugely popular on streaming devices, it could hurt sales of Amazon’s Fire TV.

Variety noted that when Google pulled YouTube from the Echo Show sales of the device declined.