diff --git a/ChangeLog b/ChangeLog
index 7104682154..411c50be13 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Feb 15 21:22:48 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/test/unit/assertions.rb (Test::Unit::Assertions): aliases
+	  assert_not_ methods.
+
 Sun Feb 15 16:57:35 2009  Tanaka Akira  <akr@fsij.org>
 
 	* lib/securerandom.rb (SecureRandom.urlsafe_base64): new method.
diff --git a/lib/test/unit/assertions.rb b/lib/test/unit/assertions.rb
index 2e9fadfe57..de357d0fea 100644
--- a/lib/test/unit/assertions.rb
+++ b/lib/test/unit/assertions.rb
@@ -122,6 +122,10 @@ EOT
         super if !caller[0].rindex(MiniTest::MINI_DIR, 0) || !obj.respond_to?(meth)
       end
 
+      instance_methods(true).grep(/\Arefute_/) do |m|
+        alias_method(('assert_not_' << m.to_s[/.*?_(.*)/, 1]), m)
+      end
+
       def build_message(head, template=nil, *arguments)
         template &&= template.chomp
         template.gsub(/\?/) { mu_pp(arguments.shift) }