diff --git a/swh/lister/cran/lister.py b/swh/lister/cran/lister.py
--- a/swh/lister/cran/lister.py
+++ b/swh/lister/cran/lister.py
@@ -72,7 +72,7 @@
                                                    'list_all_packages.R')
         logger.debug('script list-all-packages.R path: %s', filepath)
         response = subprocess.run(
-            filepath, stdout=subprocess.PIPE, shell=False)
+            filepath, stdout=subprocess.PIPE, shell=False, encoding='utf-8')
         data = json.loads(response.stdout)
         logger.debug('r-script-request: %s', data)
         return data