Twitch has begun testing a new feature called “Watch Parties,” which appears to allow streamers the ability to stream content from Amazon Prime to their viewers (who also have Amazon Prime), according to a tweet posted Friday evening. “Watch Parties brings Prime Video to Twitch,” the announcement said. “You can watch a selection of Prime Video movies and TV shows on your channel with any of your viewers who have Prime, including the new season of Tom Clancy’s Jack Ryan, Mission: Impossible - Fallout, and Pokémon.”

A spokesperson for Twitch confirmed the email is being sent to a mix of affiliates and partners for the first test group.

There’s definitely interest. As Travis Shreffler, the streamer who posted the tweets in the first place, pointed out: a couple springs ago, Twitch had a Power Rangers marathon of every episode, and let streamers co-stream it with their communities for a cool social watching experience. “You saw a lot of streamers, myself included, doing MST3K-style commentary of episodes,” Shreffler writes in an email to The Verge. “I’ve had multiple people say they want to do ‘The Boys with The Boys.’ When season 2 of Amazon’s The Boys comes out, they’re going to get together and binge it with their friends.”

Allowing streamers to feature shows also promises to bring new channels onto Twitch. Watch-alongs will probably become a more regular feature of the site as digital rights and permissions get figured out. The move likely comes in response to pressure from Twitch’s competitors — namely Caffeine, the live-streaming platform that’s currently in beta that’s attracted a $100 million investment from 21st Century Fox. (It seems likely that Caffeine’s plans include giving their streamers at least some access to some of 21st Century Fox’s catalog.)

While Twitch hosts many different kinds of streamers on its platform — and has recently beefed up its investments in sports and music content — the service is primarily known for its core focus on video games.

Allowing streamers the ability to access Amazon’s content library is a savvy move, and seems like a new front on the ongoing streaming wars; the fight for content libraries now necessarily has to include digital streaming rights. Twitch has Amazon’s deep pockets and attractive original films and television; Caffeine has Fox, which has exclusive sports and music rights that other services don’t have; YouTube has its billions of hours of video. While Twitch also has a first-mover advantage as the most popular streaming site in the world, it also needs to convince consumers that it’s for more than games.

Streamers have already figured that out. People have been streaming things illicitly on Twitch for a while — if you visit its Just Chatting category and scroll for a minute, you’ll find people streaming dubbed anime in Russian, for example, among the ubiquitous vloggers.

Some of these people are just pirating video, but enough are trying to provide transformative commentary that it seems clear there’s an appetite among streamers for a legal way to comment on live TV or event viewing. Earlier this year, some well-known streamers earned copyright strikes on their accounts because they streamed a political debate; they cited fair use, but the corporation hosting the event thought otherwise.