diff --git a/ChangeLog b/ChangeLog
index 76dcac9e9a..bb4037304b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat May 21 22:14:35 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* io.c (rb_io_extract_modeenc): accept combination hash and
+	  File::Constants. (eg. File.open('yo', :mode => File::WRONLY))
+	  [Feature #4742][ruby-core:36338]
+	* test/ruby/test_io.rb (TestIO#test_open_mode): new test.
+
 Sat May 21 21:44:14 2011  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* test/date/test_switch_hitter.rb: new.
diff --git a/io.c b/io.c
index 154a01943b..053c161e53 100644
--- a/io.c
+++ b/io.c
@@ -4458,6 +4458,7 @@ rb_io_extract_modeenc(VALUE *vmode_p, VALUE *vperm_p, VALUE opthash,
     /* Set to defaults */
     rb_io_ext_int_to_encs(NULL, NULL, &enc, &enc2);
 
+  vmode_handle:
     if (NIL_P(vmode)) {
         fmode = FMODE_READABLE | DEFAULT_TEXTMODE;
         oflags = O_RDONLY;
@@ -4470,7 +4471,6 @@ rb_io_extract_modeenc(VALUE *vmode_p, VALUE *vperm_p, VALUE opthash,
     else {
         const char *p;
 
-      vmode_handle:
         SafeStringValue(vmode);
         p = StringValueCStr(vmode);
         fmode = rb_io_modestr_fmode(p);
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index de55abbd41..1ed9072c89 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1849,4 +1849,16 @@ End
     end
     rescue NotImplementedError
   end
+
+  def test_open_mode
+    feature4742 = "[ruby-core:36338]"
+
+    mkcdtmpdir do
+      refute_nil(File.open('symbolic', 'w'))
+      refute_nil(File.open('numeric',  File::WRONLY|File::TRUNC|File::CREAT))
+      refute_nil(File.open('hash-symbolic', :mode => 'w'))
+      refute_nil(File.open('hash-numeric', :mode => File::WRONLY|File::TRUNC|File::CREAT), feature4742)
+    end
+  end
+
 end