diff --git a/functions/mhash.xml b/functions/mhash.xml
index 1cddbfae45..84063ffc86 100644
--- a/functions/mhash.xml
+++ b/functions/mhash.xml
@@ -239,7 +239,7 @@ for ($i = 0; $i <= $nr; $i++) {
    </refsect1>
   </refentry>
 
-  <refentry id="function.mhash_keygen_s2k">
+  <refentry id="function.mhash-keygen-s2k">
    <refnamediv>
     <refname>mhash_keygen_s2k</refname>
     <refpurpose>Generates a key</refpurpose>