diff --git a/functions/filesystem.xml b/functions/filesystem.xml
index 28928e4c39..33ffdd85b3 100644
--- a/functions/filesystem.xml
+++ b/functions/filesystem.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.119 $ -->
+<!-- $Revision: 1.120 $ -->
  <reference id="ref.filesystem">
   <title>Filesystem functions</title>
   <titleabbrev>Filesystem</titleabbrev>
@@ -556,7 +556,7 @@ fclose ($fp);
      <methodsynopsis>
       <type>string</type><methodname>fgets</methodname>
       <methodparam><type>int</type><parameter>fp</parameter></methodparam>
-      <methodparam><type>int</type><parameter>length</parameter></methodparam>
+      <methodparam choice="opt"><type>int</type><parameter>length</parameter></methodparam>
      </methodsynopsis>
     <para>
      Returns a string of up to length - 1 bytes read from the file
@@ -572,8 +572,8 @@ fclose ($fp);
      Common Pitfalls:
     </para>
     <simpara>
-     People used to the 'C' semantics of fgets should note the
-     difference in how EOF is returned.
+     People used to the 'C' semantics of <function>fgets</function>
+     should note the difference in how <literal>EOF</literal> is returned.
     </simpara>
     <simpara>
      The file pointer must be valid, and must point to a file
@@ -581,6 +581,12 @@ fclose ($fp);
      <function>popen</function>, or
      <function>fsockopen</function>.
     </simpara>
+    <note>
+     <para>
+      The <parameter>length</parameter> parameter is only optional in
+      PHP 4.1.0 and newer versions.
+     </para>
+    </note>
     <para>
      A simple example follows:
      <example>