diff --git a/swh/indexer/mimetype.py b/swh/indexer/mimetype.py
index a7bbe3d..8f29007 100644
--- a/swh/indexer/mimetype.py
+++ b/swh/indexer/mimetype.py
@@ -1,154 +1,156 @@
 # Copyright (C) 2016-2017  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import click
 import subprocess
 
 from swh.model import hashutil
 from swh.scheduler import utils
 
 from .indexer import BaseIndexer, DiskIndexer
 
 
 def compute_mimetype_encoding(path):
     """Determine mimetype and encoding from file at path.
 
     Args:
         path: filepath to determine the mime type
 
     Returns:
         A dict with mimetype and encoding key and corresponding values.
 
     """
     cmd = ['file', '--mime', path]
     properties = subprocess.check_output(cmd)
     if properties:
         res = properties.split(b': ')[1].strip().split(b'; ')
         mimetype = res[0]
         encoding = res[1].split(b'=')[1]
         return {
             'mimetype': mimetype,
             'encoding': encoding
         }
 
 
 class ContentMimetypeIndexer(BaseIndexer, DiskIndexer):
     """Indexer in charge of:
     - filtering out content already indexed
     - reading content from objstorage per the content's id (sha1)
     - computing {mimetype, encoding} from that content
     - store result in storage
 
     """
     ADDITIONAL_CONFIG = {
-        'workdir': ('str', '/tmp/swh/indexer.mimetype'),
-        'destination_queue': (
-            'str', 'swh.indexer.tasks.SWHOrchestratorTextContentsTask'),
+        # chained queue message, e.g:
+        # swh.indexer.tasks.SWHOrchestratorTextContentsTask
+        'destination_queue': ('str', None),
         'tool': ('dict', {
             'name': 'file',
             'version': '5.22'
         }),
     }
 
     CONFIG_BASE_FILENAME = 'indexer/mimetype'
 
     def __init__(self):
         super().__init__()
-        self.working_directory = self.config['workdir']
-        destination_queue = self.config['destination_queue']
-        self.task_destination = utils.get_task(destination_queue)
+        destination_queue = self.config.get('destination_queue')
+        if destination_queue:
+            self.task_destination = utils.get_task(destination_queue)
+        else:
+            self.task_destination = None
         self.tool_name = self.config['tool']['name']
         self.tool_version = self.config['tool']['version']
 
     def filter_contents(self, sha1s):
         """Filter out known sha1s and return only missing ones.
 
         """
         yield from self.storage.content_mimetype_missing((
             {
                 'id': sha1,
                 'tool_name': self.tool_name,
                 'tool_version': self.tool_version
             } for sha1 in sha1s
         ))
 
     def index_content(self, sha1, content):
         """Index sha1s' content and store result.
 
         Args:
             sha1 (bytes): content's identifier
             content (bytes): raw content in bytes
 
         Returns:
             A dict, representing a content_mimetype, with keys:
               - id (bytes): content's identifier (sha1)
               - mimetype (bytes): mimetype in bytes
               - encoding (bytes): encoding in bytes
 
         """
         filename = hashutil.hash_to_hex(sha1)
         content_path = self.write_to_temp(
             filename=filename,
             data=content)
 
         properties = compute_mimetype_encoding(content_path)
         properties.update({
             'id': sha1,
             'tool_name': self.tool_name,
             'tool_version': self.tool_version,
         })
 
         self.cleanup(content_path)
         return properties
 
     def persist_index_computations(self, results, policy_update):
         """Persist the results in storage.
 
         Args:
             results ([dict]): list of content_mimetype, dict with the
             following keys:
               - id (bytes): content's identifier (sha1)
               - mimetype (bytes): mimetype in bytes
               - encoding (bytes): encoding in bytes
             policy_update ([str]): either 'update-dups' or 'ignore-dups' to
             respectively update duplicates or ignore them
 
         """
         self.storage.content_mimetype_add(
             results, conflict_update=(policy_update == 'update-dups'))
 
     def _filter_text(self, results):
         """Filter sha1 whose raw content is text.
 
         """
         for result in results:
             if b'binary' in result['encoding']:
                 continue
             yield result['id']
 
     def next_step(self, results):
         """When the computations is done, we'd like to send over only text
         contents to the text content orchestrator.
 
         Args:
             results ([dict]): List of content_mimetype results, dict
             with the following keys:
               - id (bytes): content's identifier (sha1)
               - mimetype (bytes): mimetype in bytes
               - encoding (bytes): encoding in bytes
 
         """
         if self.task_destination:
             self.task_destination.delay(list(self._filter_text(results)))
 
 
 @click.command()
 @click.option('--path', help="Path to execute index on")
 def main(path):
     print(compute_mimetype_encoding(path))
 
 
 if __name__ == '__main__':
     main()