diff --git a/tools/fake_dragonxd/README.md b/tools/fake_dragonxd/README.md
index ccdd202..db438dc 100644
--- a/tools/fake_dragonxd/README.md
+++ b/tools/fake_dragonxd/README.md
@@ -84,7 +84,8 @@ something already listens on 21769, because the GUI would adopt that process as
 It also refuses a Lite-configured `--build-dir`: Lite has no embedded daemon, and any
 `bin/ObsidianDragon` in such a tree is stale.
 To "close the window" from a script, send SIGTERM to the GUI (`kill -TERM <gui pid>`); SDL turns it
-into a normal quit.
+into a normal quit. For scripted runs nobody needs to watch, add `SDL_VIDEODRIVER=offscreen`: the GUI
+runs with no window at all (OpenGL still loads, and connecting and shutting down work as usual).
 
 To run the stub alone: `FAKE_... build/linux/fake_dragonxd/dragonxd -datadir=/some/dir [-printtoconsole]`
 with a `DRAGONX.conf` (`rpcuser`/`rpcpassword`/`rpcport`) in that dir.