diff --git a/ChangeLog b/ChangeLog
index 296da1bdf6..f77871d28f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Sat Mar 13 23:48:27 2010  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* file.c (file_expand_path): should not just copy the encoding
+	  from fname.  [ruby-core:28635]
+
+	* file.c (EXPAND_PATH_BUFFER): set filesystem_encoding, not
+	  usascii for path buffer.
+
 Sat Mar 13 17:48:43 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* tool/file2lastrev.rb: refactord.  fixed changed revision of git.
diff --git a/file.c b/file.c
index aed663ac11..0874732389 100644
--- a/file.c
+++ b/file.c
@@ -2831,7 +2831,7 @@ file_expand_path(VALUE fname, VALUE dname, int abs_mode, VALUE result)
 	p = buf + (s - b);
 	BUFCHECK(bdiff >= buflen);
 	memset(buf, '/', p - buf);
-	rb_enc_copy(result, fname);
+	rb_enc_associate(result, rb_enc_check(result, fname));
     }
     if (p > buf && p[-1] == '/')
 	--p;
@@ -2998,7 +2998,7 @@ file_expand_path(VALUE fname, VALUE dname, int abs_mode, VALUE result)
     return result;
 }
 
-#define EXPAND_PATH_BUFFER() rb_usascii_str_new(0, MAXPATHLEN + 2)
+#define EXPAND_PATH_BUFFER() rb_filesystem_str_new(0, MAXPATHLEN + 2)
 
 #define check_expand_path_args(fname, dname) \
     ((fname = rb_get_path(fname)), \