diff --git a/ChangeLog b/ChangeLog
index bbe77502b8..0712bd83b7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Nov 26 20:23:49 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* test/ruby/test_argf.rb (TestArgf#test_chars): since marshal data is
+	  binary, shouldn't pass via text mode.  use base64 encoded data.
+
 Mon Nov 26 19:45:18 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* ruby_atomic.h (ATOMIC_CAS): new macro for compare-and-exchange.
diff --git a/test/ruby/test_argf.rb b/test/ruby/test_argf.rb
index a58b70db52..7fb9348c1e 100644
--- a/test/ruby/test_argf.rb
+++ b/test/ruby/test_argf.rb
@@ -781,9 +781,9 @@ class TestArgf < Test::Unit::TestCase
 
   def test_chars
     ruby('-e', <<-SRC, @t1.path, @t2.path, @t3.path) do |f|
-      print Marshal.dump(ARGF.chars.to_a)
+      print [Marshal.dump(ARGF.chars.to_a)].pack('m')
     SRC
-      assert_equal(["1", "\n", "2", "\n", "3", "\n", "4", "\n", "5", "\n", "6", "\n"], Marshal.load(f.read))
+    assert_equal(["1", "\n", "2", "\n", "3", "\n", "4", "\n", "5", "\n", "6", "\n"], Marshal.load(f.read.unpack('m').first))
     end
   end