diff --git a/ChangeLog b/ChangeLog
index 732371201d..fe8fc495fa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Jun  6 18:25:43 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* test/iconv/utils.rb (default_test): override not to croak.
+
 Fri Jun  6 16:41:45 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* include/ruby/win32.h: include ws2tcpip.h. fixed [ruby-Bugs-20528]
diff --git a/test/iconv/test_basic.rb b/test/iconv/test_basic.rb
index 12f30e4a0e..ea564e91f1 100644
--- a/test/iconv/test_basic.rb
+++ b/test/iconv/test_basic.rb
@@ -1,6 +1,6 @@
 require File.join(File.dirname(__FILE__), "utils.rb")
 
-TestIconv.testcase(:Basic) do
+class TestIconv::Basic < TestIconv
   def test_euc2sjis
     iconv = Iconv.open('SHIFT_JIS', 'EUC-JP')
     str = iconv.iconv(EUCJ_STR)
@@ -46,4 +46,4 @@ TestIconv.testcase(:Basic) do
   def test_unknown_encoding
     assert_raise(Iconv::InvalidEncoding) { Iconv.iconv("utf-8", "X-UKNOWN", "heh") }
   end
-end
+end if defined?(TestIconv)
diff --git a/test/iconv/test_option.rb b/test/iconv/test_option.rb
index f879dbaf66..a1f3457c31 100644
--- a/test/iconv/test_option.rb
+++ b/test/iconv/test_option.rb
@@ -1,6 +1,6 @@
 require File.join(File.dirname(__FILE__), "utils.rb")
 
-TestIconv.testcase(:Option) do
+class TestIconv::Option < TestIconv
   def test_ignore_option
     iconv = Iconv.new('SHIFT_JIS', 'EUC-JP//ignore')
     str = iconv.iconv(EUCJ_STR)
@@ -28,4 +28,4 @@ TestIconv.testcase(:Option) do
     assert_equal(SJIS_STR, str)
     iconv.close
   end
-end
+end if defined?(TestIconv)
diff --git a/test/iconv/test_partial.rb b/test/iconv/test_partial.rb
index 8e973b6df9..aa4d0ba250 100644
--- a/test/iconv/test_partial.rb
+++ b/test/iconv/test_partial.rb
@@ -1,6 +1,6 @@
 require File.join(File.dirname(__FILE__), "utils.rb")
 
-TestIconv.testcase(:Partial) do
+class TestIconv::Partial < TestIconv
   def test_partial_ascii
     c = Iconv.open(ASCII, ASCII)
     ref = '[ruby-core:17092]'
@@ -38,4 +38,4 @@ TestIconv.testcase(:Partial) do
   ensure
     c.close
   end
-end
+end if defined?(TestIconv)
diff --git a/test/iconv/utils.rb b/test/iconv/utils.rb
index 99dce20837..bc75deb173 100644
--- a/test/iconv/utils.rb
+++ b/test/iconv/utils.rb
@@ -5,21 +5,7 @@ else
   require 'test/unit'
 end
 
-module TestIconv
-  if defined?(::Iconv)
-    def self.testcase(name, &block)
-      const_set(name, klass = Class.new(::Test::Unit::TestCase))
-      klass.name
-      klass.__send__(:include, self)
-      klass.class_eval(&block)
-    end
-  else
-    def self.testcase(name)
-    end
-  end
-end
-
-module TestIconv
+class TestIconv < ::Test::Unit::TestCase
   if defined?(::Encoding) and String.method_defined?(:force_encoding)
     def self.encode(str, enc)
       str.force_encoding(enc)
@@ -30,6 +16,10 @@ module TestIconv
     end
   end
 
+  def default_test
+    self.class == TestIconv or super
+  end
+
   ASCII = "ascii"
   EUCJ_STR = encode("\xa4\xa2\xa4\xa4\xa4\xa6\xa4\xa8\xa4\xaa", "EUC-JP").freeze
   SJIS_STR = encode("\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8", "Shift_JIS").freeze