diff --git a/swh/lister/cran/lister.py b/swh/lister/cran/lister.py
index 3f632e6..5c8e6a2 100644
--- a/swh/lister/cran/lister.py
+++ b/swh/lister/cran/lister.py
@@ -1,132 +1,131 @@
 # Copyright (C) 2019 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 logging
 import pkg_resources
 import subprocess
 
 from typing import List, Mapping
 
 from swh.lister.cran.models import CRANModel
 
 from swh.lister.core.simple_lister import SimpleLister
 from swh.scheduler.utils import create_task_dict
 
 
 logger = logging.getLogger(__name__)
 
 
 def read_cran_data() -> List[Mapping[str, str]]:
     """Execute r script to read cran listing.
 
     """
     filepath = pkg_resources.resource_filename('swh.lister.cran',
                                                'list_all_packages.R')
     logger.debug('script list-all-packages.R path: %s', filepath)
-    response = subprocess.run(
-        filepath, stdout=subprocess.PIPE, shell=False, encoding='utf-8')
-    return json.loads(response.stdout)
+    response = subprocess.run(filepath, stdout=subprocess.PIPE, shell=False)
+    return json.loads(response.stdout.decode('utf-8'))
 
 
 def compute_package_url(repo: Mapping[str, str]) -> str:
     """Compute the package url from the repo dict.
 
     Args:
         repo: dict with key 'Package', 'Version'
 
     Returns:
         the package url
 
     """
     return 'https://cran.r-project.org/src/contrib' \
         '/%(Package)s_%(Version)s.tar.gz'.format(repo)
 
 
 class CRANLister(SimpleLister):
     MODEL = CRANModel
     LISTER_NAME = 'cran'
     instance = 'cran'
 
     def task_dict(self, origin_type, origin_url, **kwargs):
         """Return task format dict. This creates tasks with args and kwargs
         set, for example::
 
             args: ['package', 'https://cran.r-project.org/...', 'version']
             kwargs: {}
 
         """
         policy = kwargs.get('policy', 'oneshot')
         package = kwargs.get('name')
         version = kwargs.get('version')
         return create_task_dict(
             'load-%s' % origin_type,
             policy, package, origin_url, version,
             retries_left=3,
         )
 
     def safely_issue_request(self, identifier):
         """Bypass the implementation. It's now the `list_packages` which
         returns data.
 
         As an implementation detail, we cannot change simply the base
         SimpleLister yet as other implementation still uses it. This shall be
         part of another refactoring pass.
 
         """
         return None
 
     def list_packages(self, *args) -> List[Mapping[str, str]]:
         """Runs R script which uses inbuilt API to return a json response
            containing data about the R packages.
 
         Returns:
             List of Dict about r packages. For example:
 
             .. code-block:: python
 
                 [
                     {
                         'Package': 'A3',
                         'Version': '1.0.0',
                         'Title':
                             'Accurate, Adaptable, and Accessible Error Metrics
                              for Predictive\nModels',
                         'Description':
                             'Supplies tools for tabulating and analyzing the
                              results of predictive models. The methods employed
                              are ... '
                     },
                     {
                         'Package': 'abbyyR',
                         'Version': '0.5.4',
                         'Title':
                             'Access to Abbyy OCR (OCR) API',
                         'Description': 'Get text from images of text using
                                         Abbyy Cloud Optical Character\n ...'
                     },
                     ...
                 ]
 
         """
         return read_cran_data()
 
     def get_model_from_repo(
             self, repo: Mapping[str, str]) -> Mapping[str, str]:
         """Transform from repository representation to model
 
         """
         logger.debug('repo: %s', repo)
         project_url = compute_package_url(repo)
         package = repo['Package']
         return {
             'uid': package,
             'name': package,
             'full_name': repo['Title'],
             'version': repo['Version'],
             'html_url': project_url,
             'origin_url': project_url,
             'origin_type': 'tar',
         }