diff --git a/ChangeLog b/ChangeLog
index 3f739b9589..278426b33b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Wed May 21 01:28:47 2008  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* transcode.c, include/ruby/encodng.h (rb_str_transcode):
+	  C API of encoding conversion for Ruby object.
+	  VALUE rb_str_transcode(VALUE str, VALUE to).
+
+	* transcode.c (str_encode, str_encode_bang):
+	  rename from rb_tr_transcode or rb_str_transcode_bang.
+
 Tue May 20 23:26:05 2008  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* test/ruby/test_array.rb: fix tests for 64bit CPU.
diff --git a/include/ruby/encoding.h b/include/ruby/encoding.h
index 0a6b7c18e2..e5820beb7c 100644
--- a/include/ruby/encoding.h
+++ b/include/ruby/encoding.h
@@ -193,4 +193,6 @@ rb_enc_dummy_p(rb_encoding *enc)
     return ENC_DUMMY_P(ENC_FROM_ENCODING(enc));
 }
 
+VALUE rb_str_transcode(VALUE str, VALUE to);
+
 #endif /* RUBY_ENCODING_H */
diff --git a/transcode.c b/transcode.c
index c6e6a3eded..60aee66d5d 100644
--- a/transcode.c
+++ b/transcode.c
@@ -397,7 +397,7 @@ str_transcode(int argc, VALUE *argv, VALUE *self)
  */
 
 static VALUE
-rb_str_transcode_bang(int argc, VALUE *argv, VALUE str)
+str_encode_bang(int argc, VALUE *argv, VALUE str)
 {
     VALUE newstr = str;
     int encidx = str_transcode(argc, argv, &newstr);
@@ -432,10 +432,19 @@ rb_str_transcode_bang(int argc, VALUE *argv, VALUE str)
  */
 
 static VALUE
-rb_str_transcode(int argc, VALUE *argv, VALUE str)
+str_encode(int argc, VALUE *argv, VALUE str)
 {
     str = rb_str_dup(str);
-    return rb_str_transcode_bang(argc, argv, str);
+    return str_encode_bang(argc, argv, str);
+}
+
+VALUE
+rb_str_transcode(VALUE str, VALUE to)
+{
+    int argc = 1;
+    VALUE argv = rb_ary_new2(1);
+    rb_ary_push(argv, to);
+    return str_encode(argc, &argv, str);
 }
 
 void
@@ -447,6 +456,6 @@ Init_transcode(void)
     sym_invalid = ID2SYM(rb_intern("invalid"));
     sym_ignore = ID2SYM(rb_intern("ignore"));
 
-    rb_define_method(rb_cString, "encode", rb_str_transcode, -1);
-    rb_define_method(rb_cString, "encode!", rb_str_transcode_bang, -1);
+    rb_define_method(rb_cString, "encode", str_encode, -1);
+    rb_define_method(rb_cString, "encode!", str_encode_bang, -1);
 }
diff --git a/version.h b/version.h
index 29ddf70ea9..f278b39eac 100644
--- a/version.h
+++ b/version.h
@@ -1,7 +1,7 @@
 #define RUBY_VERSION "1.9.0"
-#define RUBY_RELEASE_DATE "2008-05-20"
+#define RUBY_RELEASE_DATE "2008-05-21"
 #define RUBY_VERSION_CODE 190
-#define RUBY_RELEASE_CODE 20080520
+#define RUBY_RELEASE_CODE 20080521
 #define RUBY_PATCHLEVEL 0
 
 #define RUBY_VERSION_MAJOR 1
@@ -9,7 +9,7 @@
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_YEAR 2008
 #define RUBY_RELEASE_MONTH 5
-#define RUBY_RELEASE_DAY 20
+#define RUBY_RELEASE_DAY 21
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];