diff --git a/reference/domxml/functions/DomDocument-dump-mem.xml b/reference/domxml/functions/DomDocument-dump-mem.xml
index 92cef0abcd..61d3fb7294 100644
--- a/reference/domxml/functions/DomDocument-dump-mem.xml
+++ b/reference/domxml/functions/DomDocument-dump-mem.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.2 $ -->
+<!-- $Revision: 1.3 $ -->
 <!-- splitted from ./en/functions/domxml.xml, last change in rev 1.6 -->
   <refentry id="function.DomDocument-dump-mem">
    <refnamediv>
@@ -13,6 +13,7 @@
     <methodsynopsis>
      <type>string</type><methodname>DomDocument->dump_mem</methodname>
      <methodparam choice="opt"><type>bool</type><parameter>format</parameter></methodparam>
+     <methodparam choice="opt"><type>string</type><parameter>encoding</parameter></methodparam> 
     </methodsynopsis>
     &warn.experimental.func;
     <para>