diff --git a/gtk/gtkprogressbar.c b/gtk/gtkprogressbar.c
index 53121f32ef..4517a85ba5 100644
--- a/gtk/gtkprogressbar.c
+++ b/gtk/gtkprogressbar.c
@@ -68,12 +68,12 @@
  *
  * # CSS nodes
  *
- * |[<!-- language="plain" -->
+ * ```
  * progressbar[.osd]
  * ├── [text]
  * ╰── trough[.empty][.full]
  *     ╰── progress[.pulse]
- * ]|
+ * ```
  *
  * `GtkProgressBar` has a main CSS node with name progressbar and subnodes with
  * names text and trough, of which the latter has a subnode named progress. The