python3 - io.open not redirected to fake file system

[jopalach]

def setUp(self):
    self.setUpPyfakefs()
    # Fix for python 3+; except 3.2
    #io.open = open

def test_willRedirectIoOpen(self):
     os.makedirs('install')
     file = os.path.join('install', 'sample.txt')
        with io.open(file, 'w'):
            pass
    self.assertTrue(os.path.exists(file))

this causes the following error: IOError: [Errno 2] No such file or directory: 'install\sample.txt'

Monkey patching io.open to open after setting up the fake file system seems to fix the problem for all python versions with the exception of 3.2