Volti doesn't start on Fedora 27 with i3wm

[Rat-S]

[user@computer volti-master]$ ./volti
/tmp/volti-master/src/volti/defs.py:21: PyGIWarning: Gtk was imported without specifying a version first. Use gi.require_version('Gtk', '3.0') before import to ensure that the right version gets loaded.
  from gi.repository import Gtk
Traceback (most recent call last):
  File "./volti", line 55, in <module>
    volti = main.VolumeTray()
  File "/tmp/volti-master/src/volti/gtk3/main.py", line 84, in __init__
    self.watchid = GObject.io_add_watch(fd, eventmask, self.update)
  File "/usr/lib64/python2.7/site-packages/gi/overrides/GLib.py", line 769, in io_add_watch
    channel, priority, condition, func, user_data = _io_add_watch_get_args(*args, **kwargs)
  File "/usr/lib64/python2.7/site-packages/gi/overrides/GLib.py", line 741, in _io_add_watch_get_args
    raise TypeError('expecting callback as fourth argument')
TypeError: expecting callback as fourth argument