diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index d442629ab30a09b291398eb72709f16c1e345dea..bddf6cde65d6ab57109631f0e9ef75c4d75589bf 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,5 +1,9 @@
 // $Id$
 
+Drupal 5.21, xxxx-xx-xx
+-----------------------
+
+
 Drupal 5.20, 2009-09-16
 -----------------------
 - Avoid security problems resulting from writing Drupal 6-style menu
diff --git a/modules/system/system.module b/modules/system/system.module
index 8f814f29c42c0bd4e4c87915876b87a221b0d368..3601cc946f90657e0afc6f9157b7385e76f49734 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -6,7 +6,7 @@
  * Configuration system that lets administrators modify the workings of the site.
  */
 
-define('VERSION', '5.20');
+define('VERSION', '5.21-dev');
 
 /**
  * Implementation of hook_help().