Only reject and retry when we really know the redelivered is False

celery/worker/request.py

@@ -353,7 +353,7 @@ class Request(object):
         if self.task.acks_late:
             reject_and_requeue = (self.task.reject_on_worker_lost and
                 isinstance(exc, WorkerLostError) and
-                not self.delivery_info.get('redelivered', False))
+                self.delivery_info.get('redelivered', False) is False)
             if reject_and_requeue:
                 self.reject(requeue=True)
             else: