diff --git a/ChangeLog b/ChangeLog
index 261a276058..4ba900abef 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,7 @@
-Fri Jun 10 13:01:24 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Fri Jun 10 13:04:39 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/test/unit/assertions.rb (Test::Unit::Assertions#skip): reason to
+	  skip should be explained.
 
 	* test/ruby/test_module.rb (TestModule#remove_rake_mixins): remove all
 	  module related to Rake.
diff --git a/lib/test/unit/assertions.rb b/lib/test/unit/assertions.rb
index db0679cafb..4752943aeb 100644
--- a/lib/test/unit/assertions.rb
+++ b/lib/test/unit/assertions.rb
@@ -24,6 +24,11 @@ module Test
         super
       end
 
+      def skip(msg = nil, bt = caller)
+        raise ArgumentError, "no reason to skip" unless msg
+        super
+      end
+
       def assert_block(*msgs)
         assert yield, *msgs
       end