diff --git a/usr/bin/steamos-nested-desktop b/usr/bin/steamos-nested-desktop
index b833773..f7ae36f 100755
--- a/usr/bin/steamos-nested-desktop
+++ b/usr/bin/steamos-nested-desktop
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/bash
 
 set -eu
 
@@ -28,8 +28,11 @@ ln -s $XDG_RUNTIME_DIR/pipewire* $NEW_XDG_RUNTIME_DIR/.
 ## whilst being launched by plasma-session
 mkdir $NEW_XDG_RUNTIME_DIR/bin
 cat <<EOF > $NEW_XDG_RUNTIME_DIR/bin/kwin_wayland_wrapper
-#!/bin/sh
-/usr/bin/kwin_wayland_wrapper --width 1280 --height 800 --no-lockscreen \$@
+#!/usr/bin/bash
+if [ -z "${STEAMOS_NESTED_DESKTOP_WIDTH:-}" ] && [ -z "${STEAMOS_NESTED_DESKTOP_HEIGHT:-}" ]; then
+    source /etc/default/steamos-nested-desktop
+fi
+/usr/bin/kwin_wayland_wrapper --width ${STEAMOS_NESTED_DESKTOP_WIDTH:-1280} --height ${STEAMOS_NESTED_DESKTOP_HEIGHT:-800} --no-lockscreen \$@
 EOF
 chmod a+x $NEW_XDG_RUNTIME_DIR/bin/kwin_wayland_wrapper
 export PATH=$NEW_XDG_RUNTIME_DIR/bin:$PATH