diff --git a/dotfiles/.config/sunshine/scripts/sunshine-games.sh b/dotfiles/.config/sunshine/scripts/sunshine-games.sh
new file mode 100755
index 0000000..2b0d79e
--- /dev/null
+++ b/dotfiles/.config/sunshine/scripts/sunshine-games.sh
@@ -0,0 +1,26 @@
+#!/bin/sh
+# Sunshine global_prep_cmd: make games launched during a stream open on the
+# headless stream output instead of whichever physical monitor had focus.
+#   start -> enable the "sunshine-games" Hyprland window rule (layout/windowrules.lua:
+#            steam_app_* -> workspace 9 on HEADLESS-1, fullscreen) and make
+#            HEADLESS-1 the XWayland primary output, which Wine/Proton uses for
+#            fullscreen mode changes and scaling
+#   stop  -> disable the rule and clear the primary output again
+# Games that pick their render size at launch (KOTOR etc.) otherwise come up
+# on a desk monitor and stay tiny in a corner when moved to the stream.
+
+case "$1" in
+    start)
+        hyprctl eval 'SunshineGamesRule:set_enabled(true)'
+        xrandr --output HEADLESS-1 --primary 2>/dev/null
+        ;;
+    stop)
+        hyprctl eval 'SunshineGamesRule:set_enabled(false)'
+        xrandr --noprimary 2>/dev/null
+        ;;
+    *)
+        echo "Usage: $0 start|stop" >&2
+        exit 1
+        ;;
+esac
+exit 0
diff --git a/dotfiles/.config/sunshine/sunshine.conf b/dotfiles/.config/sunshine/sunshine.conf
index 8305557..7d7e30b 100644
--- a/dotfiles/.config/sunshine/sunshine.conf
+++ b/dotfiles/.config/sunshine/sunshine.conf
@@ -2,4 +2,4 @@ audio_sink = sink-sunshine-stereo
 csrf_allowed_origins = https://xol.twhomelab.local:47990
 nvenc_preset = 4
 output_name = HEADLESS-1
-global_prep_cmd = [{"do":"/home/thomas/.config/hypr/scripts/SunshineIdle.sh start","undo":"/home/thomas/.config/hypr/scripts/SunshineIdle.sh stop"}]
+global_prep_cmd = [{"do":"/home/thomas/.config/hypr/scripts/SunshineIdle.sh start","undo":"/home/thomas/.config/hypr/scripts/SunshineIdle.sh stop"},{"do":"/home/thomas/.config/sunshine/scripts/sunshine-games.sh start","undo":"/home/thomas/.config/sunshine/scripts/sunshine-games.sh stop"}]