diff --git a/ChangeLog b/ChangeLog
index f4a21f4c2f..4b74c4c05b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jul  7 10:12:37 2009  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* io.c (rb_io_ext_int_to_encs): Set external encoding if
+	  ext==intern. [ruby-dev:38278]
+
 Mon Jul  6 08:00:10 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* enum.c (enum_to_a): should propagate taint to the return value.
diff --git a/io.c b/io.c
index bb3daf0f04..7c77358d7b 100644
--- a/io.c
+++ b/io.c
@@ -3868,7 +3868,7 @@ rb_io_ext_int_to_encs(rb_encoding *ext, rb_encoding *intern, rb_encoding **enc,
 	intern = rb_default_internal_encoding();
     if (intern == NULL || intern == (rb_encoding *)Qnil || intern == ext) {
 	/* No internal encoding => use external + no transcoding */
-	*enc = default_ext ? NULL : ext;
+	*enc = (default_ext && intern != ext) ? NULL : ext;
 	*enc2 = NULL;
     }
     else {
diff --git a/version.h b/version.h
index 7ca43543bc..87a9bea340 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "1.9.1"
 #define RUBY_RELEASE_DATE "2009-07-12"
-#define RUBY_PATCHLEVEL 221
+#define RUBY_PATCHLEVEL 222
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 9
 #define RUBY_VERSION_TEENY 1