celery.task.chords.Chord must be importable

celery/task/chords.py

@@ -12,8 +12,11 @@
 from __future__ import absolute_import
 
 from .. import current_app
+from ..local import Proxy
 from ..utils import uuid
 
+Chord = Proxy(lambda: current_app.tasks["celery.chord"])
+
 
 class chord(object):
     Chord = None