diff --git a/functions/fdf.xml b/functions/fdf.xml
index 18393a3cb0..0f7b9a5a76 100644
--- a/functions/fdf.xml
+++ b/functions/fdf.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.24 $ -->
+<!-- $Revision: 1.25 $ -->
  <reference id="ref.fdf">
   <title>Forms Data Format functions</title>
   <titleabbrev>FDF</titleabbrev>
@@ -598,6 +598,7 @@ unlink("outtest.fdf");
      </funcprototype>
     </funcsynopsis>
     <para>
+     &warn.undocumented.func;
     </para>
    </refsect1>
   </refentry>