diff --git a/reference/hash/functions/hash-pbkdf2.xml b/reference/hash/functions/hash-pbkdf2.xml
index 7058663ebd..812ec12802 100644
--- a/reference/hash/functions/hash-pbkdf2.xml
+++ b/reference/hash/functions/hash-pbkdf2.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!-- $Revision: 299488 $ -->
+<!-- $Revision$ -->
 
 <refentry xml:id="function.hash-pbkdf2" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
  <refnamediv>