getting error Received unregistered task of type 'mytasks.add'

I have written a file `mytasks.py` ``` from celery import Celery celery = Celery("tasks", broker='redis://localhost:6379/0', backend='redis') @celery.task def add(x,y): return x+y ``` and `task.py` as follow ``` from mytasks import add add.delay(1,1) ``` I have started redis server and I have started celery server. but when i m running task.py then i am getting the following error: ``` Received unregistered task of type 'mytasks.add'. The message has been ignored and discarded. Did you remember to import the module containing this task? Or maybe you are using relative imports? Please see http://bit.ly/gLye1c for more information. The full contents of the message body was: {'retries': 0, 'task': 'mytasks.add', 'eta': None, 'args': (1, 1), 'expires': None, 'callbacks': None, 'errbacks': None, 'kwargs': {}, 'id': 'a4792308-d575-4de4-8b67-26982cae2fa4', 'utc': True} (173b) Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/celery/worker/consumer.py", line 411, in on_task_received strategies[name](message, body, message.ack_log_error) KeyError: 'mytasks.add' ``` what may be the possibel reason