On October 7, 2026, Valve announced a Steam Client Preview/Beta update that sets Proton as the default for Windows binaries registered in Steam as non-Steam games. For entries in that category, Steam selects Proton without requiring users to choose a compatibility tool manually.
What the beta changes for non-Steam games
The change covers Windows binaries added to Steam’s library as non-Steam games. It concerns the default tool for those registered entries.
Other fixes in the beta
Valve also fixed a case where changing a non-Steam game’s Target binary through Browse could prevent it from launching, and a case where Steam’s Stop button failed to close a game launched by an external tool. The update adds an option to disable the screensaver while a game is running.
The beta also fixes controller reordering in Steam Input on Linux and a Steam Controller firmware issue that could leave BLE mode stuck when no host device was found.
