diff --git a/reference/stream/functions/stream-filter-register.xml b/reference/stream/functions/stream-filter-register.xml
index 78cff8e321..0bc2471592 100644
--- a/reference/stream/functions/stream-filter-register.xml
+++ b/reference/stream/functions/stream-filter-register.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.15 $ -->
+<!-- $Revision: 1.16 $ -->
 <refentry xml:id="function.stream-filter-register" xmlns="http://docbook.org/ns/docbook">
  <refnamediv>
   <refname>stream_filter_register</refname>
@@ -141,6 +141,14 @@
             or <function>stream_filter_prepend</function>.
            </entry>
           </row>
+          <row>
+           <entry><literal>FilterClass-&gt;stream</literal></entry>
+           <entry>
+            The stream resource being filtered. Maybe available only during
+            <methodname>filter</methodname> calls when the 
+            <literal>closing</literal> parameter is set to &false;.
+           </entry>
+          </row>
          </tbody>
         </tgroup>
        </informaltable>