diff --git a/chapters/config.xml b/chapters/config.xml
index 3dcfcfaa3f..493497b54e 100644
--- a/chapters/config.xml
+++ b/chapters/config.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.85 $ -->
+<!-- $Revision: 1.86 $ -->
  <chapter id="configuration">
   <title>Configuration</title>
 
@@ -96,6 +96,15 @@ include_path = ".;c:\php\lib"
         <para>
          Sets the value of the specified directive.
          Can be used only with PHP_INI_ALL and PHP_INI_PERDIR type directives.
+	 To clear a previously set value use <literal>none</literal>
+	 as the value.
+         <informalexample>
+          <programlisting role="ini">
+<![CDATA[
+php_value auto_prepend_file none
+]]>
+          </programlisting>
+         </informalexample>
         </para>
        </listitem>
       </varlistentry>