diff --git a/reference/filesystem/functions/umask.xml b/reference/filesystem/functions/umask.xml
index 4ab1b949bf..dc834835d8 100644
--- a/reference/filesystem/functions/umask.xml
+++ b/reference/filesystem/functions/umask.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.3 $ -->
+<!-- $Revision: 1.4 $ -->
 <!-- splitted from ./en/functions/filesystem.xml, last change in rev 1.2 -->
   <refentry id="function.umask">
    <refnamediv>
@@ -10,7 +10,7 @@
     <title>Description</title>
      <methodsynopsis>
       <type>int</type><methodname>umask</methodname>
-      <methodparam><type>int</type><parameter>mask</parameter></methodparam>
+      <methodparam choice='opt'><type>int</type><parameter>mask</parameter></methodparam>
      </methodsynopsis>
     <para>
      <function>umask</function> sets PHP's umask to mask &amp; 0777 and