binding is not defined while using Ghost.py

I am writing a script and having trouble even getting a basic one to work. Ghost seems to not be importing properly. I keep getting the following error:

>>>from ghost import Ghost
  File "/Library/Python/2.7/site-packages/ghost/__init__.py", line 1, in <module>
from .ghost import Ghost, Error, TimeoutError
  File "/Library/Python/2.7/site-packages/ghost/ghost.py", line 23, in <module>
    if binding is None:
NameError: name 'binding' is not defined

Nothing special in the code:

 from ghost import Ghost
 ghost = Ghost()

I have PySide and PyQt both installed and I install Ghost by doing: sudo pip install ghost