diff --git a/ChangeLog b/ChangeLog
index fbbdaeb4c4..8f9d1675f2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue May 25 16:37:39 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* misc/ruby-style.el (ruby-style-version): take revision if
+	  keyword is expanded. [ruby-dev:41408]
+
 Tue May 25 13:26:49 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* include/ruby/vm.h, include/ruby/encoding.h: add external
diff --git a/misc/ruby-style.el b/misc/ruby-style.el
index 6dc444273c..c433025dbc 100644
--- a/misc/ruby-style.el
+++ b/misc/ruby-style.el
@@ -21,7 +21,7 @@
   "Ruby style revision string.")
 
 (defconst ruby-style-version
-  (progn
+  (and
    (string-match "[0-9.]+" ruby-style-revision)
    (substring ruby-style-revision (match-beginning 0) (match-end 0)))
   "Ruby style version number.")