diff --git a/ChangeLog b/ChangeLog
index 5b535fbdf2..a55609d5a2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Jul 18 21:59:46 2012  Tanaka Akira  <akr@fsij.org>
+
+	* test/ruby/test_argf.rb: use temporally directory.
+
 Wed Jul 18 19:41:19 2012  Tanaka Akira  <akr@fsij.org>
 
 	* test/openssl/test_config.rb: remove temporally files early.
diff --git a/test/ruby/test_argf.rb b/test/ruby/test_argf.rb
index 284f34259e..f72505e00f 100644
--- a/test/ruby/test_argf.rb
+++ b/test/ruby/test_argf.rb
@@ -2,43 +2,44 @@ require 'test/unit'
 require 'timeout'
 require 'tmpdir'
 require 'tempfile'
+require 'fileutils'
 require_relative 'envutil'
 
 class TestArgf < Test::Unit::TestCase
   def setup
-    @t1 = Tempfile.new("argf-foo")
+    @tmpdir = Dir.mktmpdir
+    @tmp_count = 0
+    @t1 = make_tempfile0("argf-foo")
     @t1.binmode
     @t1.puts "1"
     @t1.puts "2"
     @t1.close
-    @t2 = Tempfile.new("argf-bar")
+    @t2 = make_tempfile0("argf-bar")
     @t2.binmode
     @t2.puts "3"
     @t2.puts "4"
     @t2.close
-    @t3 = Tempfile.new("argf-baz")
+    @t3 = make_tempfile0("argf-baz")
     @t3.binmode
     @t3.puts "5"
     @t3.puts "6"
     @t3.close
-    @tmps = [@t1, @t2, @t3]
   end
 
   def teardown
-    @tmps.each {|t|
-      bak = t.path + ".bak"
-      File.unlink bak if File.file? bak
-      t.close(true)
-    }
+    FileUtils.rmtree(@tmpdir)
+  end
+
+  def make_tempfile0(basename)
+    open("#{@tmpdir}/#{basename}-#{@tmp_count}", "w")
   end
 
   def make_tempfile
-    t = Tempfile.new("argf-qux")
+    t = make_tempfile0("argf-qux")
     t.puts "foo"
     t.puts "bar"
     t.puts "baz"
     t.close
-    @tmps << t
     t
   end
 
@@ -417,11 +418,11 @@ class TestArgf < Test::Unit::TestCase
       end
     end
 
-    t1 = Tempfile.new("argf-foo")
+    t1 = open("#{@tmpdir}/argf-hoge", "w")
     t1.binmode
     t1.puts "foo"
     t1.close
-    t2 = Tempfile.new("argf-bar")
+    t2 = open("#{@tmpdir}/argf-moge", "w")
     t2.binmode
     t2.puts "bar"
     t2.close