diff --git a/ChangeLog b/ChangeLog
index 839a063c09..dfed835c77 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Oct  3 21:19:46 2016  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
+
+	* lib/logger.rb: [DOC] Fix default value of shift_age.
+
 Mon Oct  3 17:20:05 2016  George Brocklehurst  <ruby@georgebrock.com>
 
 	* ext/readline/readline.c (readline_s_set_quoting_detection_proc):
diff --git a/lib/logger.rb b/lib/logger.rb
index 8551abc7ac..a81b7cc182 100644
--- a/lib/logger.rb
+++ b/lib/logger.rb
@@ -340,7 +340,7 @@ class Logger
 
   #
   # :call-seq:
-  #   Logger.new(logdev, shift_age = 7, shift_size = 1048576)
+  #   Logger.new(logdev, shift_age = 0, shift_size = 1048576)
   #   Logger.new(logdev, shift_age = 'weekly')
   #   Logger.new(logdev, level: :info)
   #   Logger.new(logdev, progname: 'progname')