diff --git a/swh/indexer/mimetype.py b/swh/indexer/mimetype.py
index c427671..8bbbf64 100644
--- a/swh/indexer/mimetype.py
+++ b/swh/indexer/mimetype.py
@@ -1,152 +1,158 @@
 # 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 magic
 
+from swh.model import hashutil
 from swh.scheduler import utils
 
 from .indexer import ContentIndexer
 
 
 def compute_mimetype_encoding(raw_content):
     """Determine mimetype and encoding from the raw content.
 
     Args:
         raw_content (bytes): content's raw data
 
     Returns:
         A dict with mimetype and encoding key and corresponding values
         (as bytes).
 
     """
     r = magic.detect_from_content(raw_content)
     return {
         'mimetype': r.mime_type.encode('utf-8'),
         'encoding': r.encoding.encode('utf-8'),
     }
 
 
 class ContentMimetypeIndexer(ContentIndexer):
     """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 = {
         'destination_queue': ('str', None),
         'tools': ('dict', {
             'name': 'file',
             'version': '1:5.30-1+deb9u1',
             'configuration': {
                 "type": "library",
                 "debian-package": "python3-magic"
             },
         }),
     }
 
     CONFIG_BASE_FILENAME = 'indexer/mimetype'
 
     def prepare(self):
         super().prepare()
         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 = self.tools[0]
 
     def filter(self, ids):
         """Filter out known sha1s and return only missing ones.
 
         """
         yield from self.storage.content_mimetype_missing((
             {
                 'id': sha1,
                 'indexer_configuration_id': self.tool['id'],
             } for sha1 in ids
         ))
 
     def index(self, id, data):
         """Index sha1s' content and store result.
 
         Args:
             id (bytes): content's identifier
             data (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
 
         """
-        properties = compute_mimetype_encoding(data)
-        properties.update({
-            'id': id,
-            'indexer_configuration_id': self.tool['id'],
-        })
+        try:
+            properties = compute_mimetype_encoding(data)
+            properties.update({
+                'id': id,
+                'indexer_configuration_id': self.tool['id'],
+                })
+        except TypeError:
+            self.log.error('Detecting mimetype error for id %s' % (
+                hashutil.hash_to_hex(id), ))
+            return None
 
         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):
     with open(path, 'rb') as f:
         raw_content = f.read()
 
     print(compute_mimetype_encoding(raw_content))
 
 
 if __name__ == '__main__':
     main()