diff --git a/swh/lister/core/lister_transports.py b/swh/lister/core/lister_transports.py
index 4126d38..020eece 100644
--- a/swh/lister/core/lister_transports.py
+++ b/swh/lister/core/lister_transports.py
@@ -1,104 +1,108 @@
 # Copyright (C) 2017 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import abc
 import random
 from datetime import datetime
 from email.utils import parsedate
 from pprint import pformat
 
 import requests
+import vcversioner
 import xmltodict
 
 from .abstractattribute import AbstractAttribute
 from .lister_base import FetchError
 
 
 class SWHListerHttpTransport(abc.ABC):
     """Use the Requests library for making Lister endpoint requests.
 
     To be used in conjunction with SWHListerBase or a subclass of it.
     """
 
     PATH_TEMPLATE = AbstractAttribute('string containing a python string'
                                       ' format pattern that produces the API'
                                       ' endpoint path for listing stored'
                                       ' repositories when given an index.'
                                       ' eg. "/repositories?after=%s".'
                                       'To be implemented in the API-specific'
                                       ' class inheriting this.')
 
     EXPECTED_STATUS_CODES = (200, 429, 403, 404)
 
     def request_headers(self):
         """Returns dictionary of any request headers needed by the server.
 
         MAY BE OVERRIDDEN if request headers are needed.
         """
-        return {}
+        return {
+            'User-Agent': 'Software Heritage lister (%s)' % self.lister_version
+        }
 
     def transport_quota_check(self, response):
         """Implements SWHListerBase.transport_quota_check with standard 429 code
             check for HTTP with Requests library.
 
         MAY BE OVERRIDDEN if the server notifies about rate limits in a
             non-standard way that doesn't use HTTP 429 and the Retry-After
             response header. ( https://tools.ietf.org/html/rfc6585#section-4 )
         """
         if response.status_code == 429:  # HTTP too many requests
             retry_after = response.headers.get('Retry-After', self.back_off())
             try:
                 # might be seconds
                 return True, float(retry_after)
             except:
                 # might be http-date
                 at_date = datetime(*parsedate(retry_after)[:6])
                 from_now = (at_date - datetime.today()).total_seconds() + 5
                 return True, max(0, from_now)
         else:  # response ok
             self.reset_backoff()
             return False, 0
 
     def __init__(self, api_baseurl=None):
         if not api_baseurl:
             raise NameError('HTTP Lister Transport requires api_baseurl.')
         self.api_baseurl = api_baseurl  # eg. 'https://api.github.com'
         self.session = requests.Session()
+        self.lister_version = vcversioner.find_version().version
 
     def transport_request(self, identifier):
         """Implements SWHListerBase.transport_request for HTTP using Requests.
         """
         path = self.PATH_TEMPLATE % identifier
         params = {}
         params['headers'] = self.request_headers() or {}
         creds = self.config['credentials']
         auth = random.choice(creds) if creds else None
         if auth:
             params['auth'] = (auth['username'], auth['password'])
         try:
             response = self.session.get(self.api_baseurl + path, **params)
         except requests.exceptions.ConnectionError as e:
             raise FetchError(e)
         else:
             if response.status_code not in self.EXPECTED_STATUS_CODES:
                 raise FetchError(response)
             return response
 
     def transport_response_to_string(self, response):
         """Implements SWHListerBase.transport_response_to_string for HTTP given
             Requests responses.
         """
         s = pformat(response.request.path_url)
         s += '\n#\n' + pformat(response.request.headers)
         s += '\n#\n' + pformat(response.status_code)
         s += '\n#\n' + pformat(response.headers)
         s += '\n#\n'
         try:  # json?
             s += pformat(response.json())
         except:  # not json
             try:  # xml?
                 s += pformat(xmltodict.parse(response.text))
             except:  # not xml
                 s += pformat(response.text)
         return s