diff --git a/functions/pcre.xml b/functions/pcre.xml
index c942fa4277..bb75777b76 100644
--- a/functions/pcre.xml
+++ b/functions/pcre.xml
@@ -840,6 +840,16 @@ $fl_array = preg_grep ("/^(\d+)?\.\d+$/", $array);
 	 </simpara>
 	</listitem>
        </varlistentry>
+       <varlistentry>
+	<term><emphasis>u</emphasis> (PCRE_UTF8)</term>
+	<listitem>
+	 <simpara>
+	  This modifier turns on additional functionality of PCRE that
+	  is incompatible with Perl. Pattern strings are treated as
+	  UTF-8. This modifier is available from PHP 4.0.7 or greater.
+	 </simpara>
+	</listitem>
+       </varlistentry>
       </variablelist>
      </blockquote>
     </para>