diff --git a/ChangeLog b/ChangeLog
index a892b301b0..1e62df2c99 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat May 23 18:38:46 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* man/*.1: updated dates in man pages.
+	  [ruby-dev:48988] [Bug #11171]
+
 Sat May 23 03:10:58 2015  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/win32.c (rb_w32_write_console): should return the count of
diff --git a/man/erb.1 b/man/erb.1
index 8c47e581d3..05d8f5634b 100644
--- a/man/erb.1
+++ b/man/erb.1
@@ -1,5 +1,5 @@
 .\"Ruby is copyrighted by Yukihiro Matsumoto <matz@netlab.jp>.
-.Dd November 7, 2012
+.Dd November 15, 2012
 .Dt ERB(1) "" "Ruby Programmers Reference Guide"
 .Os UNIX
 .Sh NAME
diff --git a/man/goruby.1 b/man/goruby.1
index 62a7bad23f..857874f070 100644
--- a/man/goruby.1
+++ b/man/goruby.1
@@ -1,5 +1,5 @@
 .\"Ruby is copyrighted by Yukihiro Matsumoto <matz@netlab.jp>.
-.Dd November 7, 2012
+.Dd November 15, 2012
 .Dt GORUBY(1) "" "Ruby Programmers Reference Guide"
 .Os UNIX
 .Sh NAME
diff --git a/man/irb.1 b/man/irb.1
index 543217e099..1f1800d45d 100644
--- a/man/irb.1
+++ b/man/irb.1
@@ -1,5 +1,5 @@
 .\"Ruby is copyrighted by Yukihiro Matsumoto <matz@netlab.jp>.
-.Dd November 7, 2012
+.Dd November 15, 2012
 .Dt IRB(1) "" "Ruby Programmers Reference Guide"
 .Os UNIX
 .Sh NAME
diff --git a/man/ri.1 b/man/ri.1
index cadf4b8e16..bf4efb1ac3 100644
--- a/man/ri.1
+++ b/man/ri.1
@@ -1,5 +1,5 @@
 .\"Ruby is copyrighted by Yukihiro Matsumoto <matz@netlab.jp>.
-.Dd November 7, 2012
+.Dd July 10, 2013
 .Dt RI(1) "" "Ruby Programmers Reference Guide"
 .Os UNIX
 .Sh NAME
diff --git a/man/ruby.1 b/man/ruby.1
index c35f130557..5f13a0f4ed 100644
--- a/man/ruby.1
+++ b/man/ruby.1
@@ -1,5 +1,5 @@
 .\"Ruby is copyrighted by Yukihiro Matsumoto <matz@netlab.jp>.
-.Dd November 7, 2012
+.Dd December 15, 2014
 .Dt RUBY(1) "" "Ruby Programmers Reference Guide"
 .\".Dt RUBY 1
 .Os UNIX