diff --git a/swh/storage/remote_storage.py b/swh/storage/remote_storage.py
index a2270593..67858c9f 100644
--- a/swh/storage/remote_storage.py
+++ b/swh/storage/remote_storage.py
@@ -1,98 +1,98 @@
 # Copyright (C) 2015  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 json
 
 import requests
 
 from swh.core.hashutil import hash_to_hex
 from swh.core.json import SWHJSONDecoder, SWHJSONEncoder
 
 
 class RemoteStorage():
     """Proxy to a remote storage API"""
     def __init__(self, base_url):
         self.base_url = base_url
 
     def url(self, endpoint):
         return '%s%s' % (self.base_url, endpoint)
 
     def post(self, endpoint, data):
         raw_data = json.dumps(data, cls=SWHJSONEncoder)
         response = requests.post(
             self.url(endpoint),
             data=raw_data,
             headers={'content-type': 'application/json; charset=utf8'},
         )
 
         return response.json(cls=SWHJSONDecoder)
 
     def post_files(self, endpoint, data, files):
         raw_data = json.dumps(data, cls=SWHJSONEncoder)
-        files['data'] = raw_data
+        files['metadata'] = raw_data
         response = requests.post(
             self.url(endpoint),
             files=files,
         )
 
         return response.json(cls=SWHJSONDecoder)
 
     def get(self, endpoint, data):
         response = requests.get(
             self.url(endpoint),
             params=data,
         )
 
         if response.status_code == 404:
             return None
         else:
             return response.json(cls=SWHJSONDecoder)
 
     def content_add(self, content):
         files = {}
         for file in content:
             file_id = hash_to_hex(file['sha1'])
             files[file_id] = file.pop('data')
         return self.post_files('content/add', {'content': content}, files)
 
     def content_missing(self, content, key_hash='sha1'):
         return self.post('content/missing', {'content': content,
                                              'key_hash': key_hash})
 
     def directory_add(self, directories):
         return self.post('directory/add', {'directories': directories})
 
     def directory_missing(self, directories):
         return self.post('directory/missing', {'directories': directories})
 
     def directory_get(self, directory):
         return [tuple(entry)
                 for entry in self.get('directory', {'directory': directory})]
 
     def revision_add(self, revisions):
         return self.post('revision/add', {'revisions': revisions})
 
     def revision_missing(self, revisions):
         return self.post('revision/missing', {'revisions': revisions})
 
     def release_add(self, releases):
         return self.post('release/add', {'releases': releases})
 
     def release_missing(self, releases):
         return self.post('release/missing', {'releases': releases})
 
     def occurrence_add(self, occurrences):
         return self.post('occurrence/add', {'occurrences': occurrences})
 
     def origin_get(self, origin):
         origin = self.get('origin', origin)
 
         if not origin:
             return None
         else:
             return origin['id']
 
     def origin_add_one(self, origin):
         return self.post('origin', {'origin': origin})