eSports skin betting has taken another hit after the Twitch live streaming video platform warned its users to stop promoting gambling activity.

On Wednesday, just hours after games developer Valve Corporation said it would no longer permit third-party gambling sites to access its Steam marketplace, Twitch posted a blog message warning users that “content in which the broadcaster uses or promotes services that violate Valve’s stated restrictions is prohibited on Twitch.”

eSports has become a mainstay of Twitch programming, responsible for more than one-fifth of total viewership, according to some estimates. Valve titles like Counter-Strike: Global Offensive and Dota 2 are among the most popular eSports titles streamed via the platform.

The past few weeks haven’t been kind to eSports, with Valve hit by class action lawsuits for allegedly facilitating skin betting by minors as young as 13 years old. Then there’s the ongoing revelations of eSports stars publicly shilling for skin betting sites without revealing their ownership of said sites.