flake8でAttributeErrorが発生します

###前提・実現したいこと
python2.7, CENTOS6.5でコーディングしています。

flake8を実行すると以下のようなエラーが発生します。
どなたか原因、対応方法をご存知の方いませんか？

###発生している問題・エラーメッセージ
Traceback (most recent call last):
File "/home/fm/.pyenv/versions/2.7.11/bin/flake8", line 11, in <module>
sys.exit(main())
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/main/cli.py", line 16, in main
app.run(argv)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/main/application.py", line 316, in run
self._run(argv)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/main/application.py", line 299, in _run
self.initialize(argv)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/main/application.py", line 290, in initialize
self.register_plugin_options()
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/main/application.py", line 150, in register_plugin_options
self.check_plugins.register_options(self.option_manager)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/plugins/manager.py", line 457, in register_options
list(self.manager.map(register_and_enable))
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/plugins/manager.py", line 267, in map
yield func(self.plugins[name], *args, **kwargs)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/plugins/manager.py", line 453, in register_and_enable
call_register_options(plugin)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/plugins/manager.py", line 363, in generated_function
return method(optmanager, *args, **kwargs)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8/plugins/manager.py", line 213, in register_options
add_options(optmanager)
File "/home/fm/.pyenv/versions/2.7.11/lib/python2.7/site-packages/flake8_pep257.py", line 80, in add_options
parser.config_options.append('show-pep257')
AttributeError: 'OptionManager' object has no attribute 'config_options'