+ xcb_window_t parent_win = scr->root;
+
+ /* Check whether the composite extension is available */
+ const xcb_query_extension_reply_t *extension_query = NULL;
+ xcb_generic_error_t *error = NULL;
+ xcb_composite_get_overlay_window_cookie_t cookie;
+ xcb_composite_get_overlay_window_reply_t *composite_reply = NULL;
+
+ extension_query = xcb_get_extension_data(conn, &xcb_composite_id);
+ if (extension_query && extension_query->present) {
+ /* When composition is used, we need to use the composite overlay
+ * window instead of the normal root window to be able to cover
+ * composited windows */
+ cookie = xcb_composite_get_overlay_window(conn, scr->root);
+ composite_reply = xcb_composite_get_overlay_window_reply(conn, cookie, &error);
+
+ if (!error && composite_reply) {
+ parent_win = composite_reply->overlay_win;
+ }
+
+ free(composite_reply);
+ free(error);
+ }