I don't think you need to explicitly define failed queues in ``QUEUES``, we can simply use the connection parameters from the named queue. For example if I have ``QUEUES`` like this:

```python
RQ_QUEUES = {
    'default': {
        'HOST': 'localhost',
        'PORT': 6379,
        'DB': 0,
        'PASSWORD': 'some-password',
    },
    'high': {
        'URL': os.getenv('REDISTOGO_URL', 'redis://localhost:6379'), # If you're on Heroku
        'DB': 0,
    },
    'low': {
        'HOST': 'localhost',
        'PORT': 6379,
        'DB': 0,
    }
}
```

To get the failed queue for ``high`` I should simply do ``failed_queue = get_failed_queue('high')``. Similarly, to get the failed queue for ``low`` I would just do ``failed_queue = get_failed_queue('low')``