diff --git a/ChangeLog b/ChangeLog
index 94bd6e9ca2..1c96edada3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Aug 15 01:05:39 2008  Tanaka Akira  <akr@fsij.org>
+
+	* transcode.c (econv_primitive_convert): set destination_buffer
+	  encoding.
+
 Fri Aug 15 00:52:40 2008  Tanaka Akira  <akr@fsij.org>
 
 	* include/ruby/encoding.h (rb_econv_output): declared.
diff --git a/test/ruby/test_econv.rb b/test/ruby/test_econv.rb
index 98ed310504..af846ad45b 100644
--- a/test/ruby/test_econv.rb
+++ b/test/ruby/test_econv.rb
@@ -31,6 +31,14 @@ class TestEncodingConverter < Test::Unit::TestCase
     assert_equal(Encoding::EUC_JP, ec.destination_encoding)
   end
 
+  def test_result_encoding
+    ec = Encoding::Converter.new("UTF-8", "EUC-JP")
+    dst = "".force_encoding("ASCII-8BIT")
+    assert_equal(Encoding::ASCII_8BIT, dst.encoding)
+    ec.primitive_convert("\u{3042}", dst, nil, 10)
+    assert_equal(Encoding::EUC_JP, dst.encoding)
+  end
+
   def test_output_region
     ec = Encoding::Converter.new("UTF-8", "EUC-JP")
     ec.primitive_convert(src="a", dst="b", nil, 1, Encoding::Converter::PARTIAL_INPUT)
diff --git a/transcode.c b/transcode.c
index b8c8d1a1ae..2e189b935b 100644
--- a/transcode.c
+++ b/transcode.c
@@ -1676,6 +1676,10 @@ econv_primitive_convert(int argc, VALUE *argv, VALUE self)
     rb_str_set_len(output, op-(unsigned char *)RSTRING_PTR(output));
     rb_str_drop_bytes(input, ip - (unsigned char *)RSTRING_PTR(input));
 
+    if (ec->destination_encoding) {
+        rb_enc_associate(output, ec->destination_encoding);
+    }
+
     switch (res) {
       case econv_invalid_byte_sequence: return ID2SYM(rb_intern("invalid_byte_sequence"));
       case econv_undefined_conversion: return ID2SYM(rb_intern("undefined_conversion"));