diff --git a/ChangeLog b/ChangeLog
index 79c977e689..2f48ce3277 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Nov 26 10:57:49 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/bigdecimal/bigdecimal.gemspec: revert Gem::Specification#date
+	  for snapshot/release tarballs.
+
 Tue Nov 26 06:42:50 2013  Aman Gupta <ruby@tmm1.net>
 
 	* NEWS: Add ObjectSpace.after_gc_{start,end}_hook=
diff --git a/ext/bigdecimal/bigdecimal.gemspec b/ext/bigdecimal/bigdecimal.gemspec
index e4be60ac3b..676e05bacb 100644
--- a/ext/bigdecimal/bigdecimal.gemspec
+++ b/ext/bigdecimal/bigdecimal.gemspec
@@ -1,9 +1,11 @@
 # -*- ruby -*-
 _VERSION = "1.2.3"
+date = %w$Date::                           $[1]
 
 Gem::Specification.new do |s|
   s.name = "bigdecimal"
   s.version = _VERSION
+  s.date = date
   s.summary = "Arbitrary-precision decimal floating-point number library."
   s.homepage = "http://www.ruby-lang.org"
   s.email = "mrkn@mrkn.jp"