diff --git a/docs/reference/gtk/gtk-docs.sgml b/docs/reference/gtk/gtk-docs.sgml
index 0c50347469..5b356b84c3 100644
--- a/docs/reference/gtk/gtk-docs.sgml
+++ b/docs/reference/gtk/gtk-docs.sgml
@@ -500,6 +500,10 @@ that is, GUI components such as #GtkButton or #GtkTextView.
     <title>Index of new symbols in 2.20</title>
     <xi:include href="xml/api-index-2.20.xml"><xi:fallback /></xi:include>
   </index>
+  <index id="api-index-2-22" role="2.22">
+    <title>Index of new symbols in 2.20</title>
+    <xi:include href="xml/api-index-2.22.xml"><xi:fallback /></xi:include>
+  </index>
 
   <xi:include href="xml/annotation-glossary.xml"><xi:fallback /></xi:include>