diff --git a/ChangeLog b/ChangeLog
index b8807054fc..86fa364fa3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu May 27 23:29:18 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* file.c (file_expand_path): set encoding as the same of fname
+	  when _result_ is not filesystem encoding. [ruby-dev:41429]
+
 Thu May 27 23:07:45 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* file.c (file_expand_path): use rb_enc_associate_index and
diff --git a/file.c b/file.c
index 8f1a8a8c64..ed033a71af 100644
--- a/file.c
+++ b/file.c
@@ -2895,6 +2895,7 @@ file_expand_path(VALUE fname, VALUE dname, int abs_mode, VALUE result)
 		xfree(dir);
 		rb_enc_associate_index(result, rb_filesystem_encindex());
 	    }
+	    else rb_enc_copy(result, fname);
 	    p = chompdirsep(skiproot(buf));
 	    s += 2;
 	}
@@ -2904,6 +2905,7 @@ file_expand_path(VALUE fname, VALUE dname, int abs_mode, VALUE result)
 	if (!NIL_P(dname)) {
 	    file_expand_path(dname, Qnil, abs_mode, result);
 	    BUFINIT();
+	    rb_enc_copy(result, fname);
 	}
 	else {
 	    char *dir = my_getcwd();