diff --git a/en_US.ISO8859-1/articles/contributors/contrib.additional.sgml b/en_US.ISO8859-1/articles/contributors/contrib.additional.sgml
index 57418abf7a..a8a60b80c9 100644
--- a/en_US.ISO8859-1/articles/contributors/contrib.additional.sgml
+++ b/en_US.ISO8859-1/articles/contributors/contrib.additional.sgml
@@ -3387,6 +3387,11 @@
 	<email>tamaru@ap.t.u-tokyo.ac.jp</email></para>
     </listitem>
 
+    <listitem>
+      <para>Hirohisa Yamaguchi
+	<email>umq@ueo.co.jp</email></para>
+    </listitem>
+
     <listitem>
       <para>Hironori Ikura
 	<email>hikura@kaisei.org</email></para>