diff --git a/swh/indexer/ctags.py b/swh/indexer/ctags.py
index 6bd42cb..f5bd817 100644
--- a/swh/indexer/ctags.py
+++ b/swh/indexer/ctags.py
@@ -1,148 +1,150 @@
 # Copyright (C) 2015-2016  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
 import json
 
 from swh.core import hashutil
 
 from .language import compute_language
 from .indexer import BaseIndexer, DiskIndexer
 
 
 # Options used to compute tags
 __FLAGS = [
     '--fields=+lnz',  # +l: language
                       # +n: line number of tag definition
                       # +z: include the symbol's kind (function, variable, ...)
     '--sort=no',      # sort output on tag name
     '--links=no',     # do not follow symlinks
     '--output-format=json',  # outputs in json
 ]
 
 
 def run_ctags(path, lang=None, ctags_binary='ctags'):
     """Run ctags on file path with optional language.
 
     Args:
         path: path to the file
         lang: language for that path (optional)
 
     Returns:
         ctags' output
 
     """
     optional = []
     if lang:
         optional = ['--language-force=%s' % lang]
 
     cmd = [ctags_binary] + __FLAGS + optional + [path]
     output = subprocess.check_output(cmd, universal_newlines=True)
 
     for symbol in output.split('\n'):
         if not symbol:
             continue
         js_symbol = json.loads(symbol)
         yield {
             'name': js_symbol['name'],
             'kind': js_symbol['kind'],
             'line': js_symbol['line'],
             'lang': js_symbol['language'],
         }
 
 
 class CtagsIndexer(BaseIndexer, DiskIndexer):
     CONFIG_BASE_FILENAME = 'indexer/ctags'
 
     ADDITIONAL_CONFIG = {
         'ctags': ('str', '/usr/bin/ctags'),
         'workdir': ('str', '/tmp/swh/indexer.ctags'),
         'languages': ('dict', {
             'ada': 'Ada',
             'adl': None,
             'agda': None,
             # ...
         })
     }
 
     def __init__(self):
         super().__init__()
         self.working_directory = self.config['workdir']
         self.language_map = self.config['languages']
         self.ctags_binary = self.config['ctags']
 
     def filter_contents(self, sha1s):
         """Filter out known sha1s and return only missing ones.
 
         """
         yield from self.storage.content_ctags_missing(sha1s)
 
     def index_content(self, sha1, raw_content):
         """Index sha1s' content and store result.
 
         Args:
             sha1 (bytes): content's identifier
             raw_content (bytes): raw content in bytes
 
         Returns:
             A dict, representing a content_mimetype, with keys:
               - id (bytes): content's identifier (sha1)
               - ctags ([dict]): ctags list of symbols
 
         """
         lang = compute_language(raw_content)['lang']
 
         if not lang:
             return None
 
         ctags_lang = self.language_map.get(lang)
 
         if not ctags_lang:
             return None
 
         ctags = {
             'id': sha1,
         }
 
         filename = hashutil.hash_to_hex(sha1)
         content_path = self.write_to_temp(
             filename=filename,
             data=raw_content)
 
         result = run_ctags(content_path,
                            lang=ctags_lang,
                            ctags_binary=self.ctags_binary)
         ctags.update({
             'ctags': list(result),
         })
 
         self.cleanup(content_path)
 
         return ctags
 
     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)
               - ctags ([dict]): ctags list of symbols
-            policy_update ([str]): unused in this context
+            policy_update ([str]): either 'update-dups' or 'ignore-dups' to
+            respectively update duplicates or ignore them
 
         """
-        self.storage.content_ctags_add(results)
+        self.storage.content_ctags_add(
+            results, conflict_update=(policy_update == 'update-dups'))
 
 
 @click.command()
 @click.option('--path', help="Path to execute index on")
 def main(path):
     r = list(run_ctags(path))
     print(r)
 
 
 if __name__ == '__main__':
     main()