diff --git a/stable/xdg-shell/xdg-shell.xml b/stable/xdg-shell/xdg-shell.xml
index 4b23b48fa482699b41c7290decc574ab05742520..9ef284e5e2ca750965e17f1925ca5085a010a677 100644
--- a/stable/xdg-shell/xdg-shell.xml
+++ b/stable/xdg-shell/xdg-shell.xml
@@ -344,7 +344,7 @@
 
 	The default adjustment is none.
       </description>
-      <arg name="constraint_adjustment" type="uint"
+      <arg name="constraint_adjustment" type="uint" enum="constraint_adjustment"
 	   summary="bit mask of constraint adjustments"/>
     </request>