Cyrillic filenames throws error

[Yumash]

 * work/Docs/файл кириллик.txt | New file
Traceback (most recent call last):
  File "./codediff.py", line 831, in <module>
    differ.make_diff()
  File "./codediff.py", line 723, in make_diff
    self.__diff_dir()
  File "./codediff.py", line 712, in __diff_dir
    self.__diff_dir_by_list()
  File "./codediff.py", line 590, in __diff_dir_by_list
    write_file(target + '.html', convert_to_html(obj2))
  File "./codediff.py", line 126, in convert_to_html
    html += html_filter(s)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd0 in position 55: ordinal not in range(128)