TypeError in pyptlib subproc on Windows

Running obfs-flash-client on Windows gives me this error:

Traceback (most recent call last):
  File "obfs-flash-client", line 11, in <module>
    from pyptlib.util.subproc import auto_killall, Popen
  File "pyptlib\util\subproc.py", line 31, in <module>
    _Popen_defaults['creationflags'] |= subprocess.CREATE_NEW_PROCESS_GROUP
TypeError: list indices must be integers, not str