diff --git a/ChangeLog b/ChangeLog
index 932ace7c37..38010340b6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Mon Jun  2 21:56:47 2008  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* test/ruby/test_file.rb: add tests for uninitialized object.
+
+	* test/ruby/test_class.rb: ditto.
+
+	* test/ruby/test_thread.rb: ditto.
+
 Mon Jun  2 21:44:15 2008  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* re.c: fix SEGV by Regexp.allocate.names, Match.allocate.names, etc.
diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 8c035b5d59..b45c70ae5e 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -146,4 +146,9 @@ class TestClass < Test::Unit::TestCase
       assert_equal(":foo\n:foo\ntrue\ntrue", r.read.chomp)
     end
   end
+
+  def test_uninitialized
+    assert_raise(TypeError) { Class.allocate.new }
+    assert_raise(TypeError) { Class.allocate.superclass }
+  end
 end
diff --git a/test/ruby/test_file.rb b/test/ruby/test_file.rb
index 22dc1a89e5..26b29785ab 100644
--- a/test/ruby/test_file.rb
+++ b/test/ruby/test_file.rb
@@ -115,4 +115,7 @@ class TestFile < Test::Unit::TestCase
     }
   end
 
+  def test_uninitialized
+    assert_raise(TypeError) { File::Stat.allocate.readable? }
+  end
 end
diff --git a/test/ruby/test_thread.rb b/test/ruby/test_thread.rb
index 9abe39b104..e3a6724425 100644
--- a/test/ruby/test_thread.rb
+++ b/test/ruby/test_thread.rb
@@ -499,4 +499,10 @@ class TestThreadGroup < Test::Unit::TestCase
     }.join
     t.join
   end
+
+  def test_uninitialized
+    c = Class.new(Thread)
+    c.class_eval { def initialize; end }
+    assert_raise(ThreadError) { c.new.start }
+  end
 end