diff --git a/prism/CHANGELOG.txt b/prism/CHANGELOG.txt
index 6cde3d88..fbce1a3b 100644
--- a/prism/CHANGELOG.txt
+++ b/prism/CHANGELOG.txt
@@ -1,7 +1,7 @@
 This file contains details of the changes in each new version of PRISM.
 
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-Version 4.1 (beta released ???)
+Version 4.1 (beta released 20/12/2012)
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 * Multi-objective model checking for MDPs