diff --git a/ChangeLog b/ChangeLog
index f3eb10e7d3..1e6e991c0e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Dec 22 01:23:10 2007  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* test/json/test_json_addition.rb (test_core): do not use Time.now
+	  because JSON can't hold nsec.
+
 Sat Dec 22 01:10:30 2007  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* ext/tk/sample/tkextlib/vu/canvSticker2.rb,
diff --git a/test/json/test_json_addition.rb b/test/json/test_json_addition.rb
index 2ae0ce47c5..e8ae41525f 100755
--- a/test/json/test_json_addition.rb
+++ b/test/json/test_json_addition.rb
@@ -112,7 +112,7 @@ EOT
   end
 
   def test_core
-    t = Time.now
+    t = Time.at(1198254128, 895990)
     assert_equal t, JSON(JSON(t))
     d = Date.today
     assert_equal d, JSON(JSON(d))