diff --git a/swh/lister/sourceforge/lister.py b/swh/lister/sourceforge/lister.py
--- a/swh/lister/sourceforge/lister.py
+++ b/swh/lister/sourceforge/lister.py
@@ -10,7 +10,6 @@
 from typing import Any, Dict, Iterator, List, Optional, Set, Tuple
 from xml.etree import ElementTree
 
-import iso8601
 import requests
 from tenacity.before_sleep import before_sleep_log
 
@@ -248,11 +247,14 @@
     ) -> Iterator[ListedOrigin]:
         assert self.lister_obj.id is not None
         for hit in page:
+            last_update = datetime.datetime.combine(
+                hit.last_modified, datetime.time(tzinfo=datetime.timezone.utc)
+            )
             yield ListedOrigin(
                 lister_id=self.lister_obj.id,
                 visit_type=hit.vcs.value,
                 url=hit.url,
-                last_update=iso8601.parse_date(hit.last_modified),
+                last_update=last_update,
             )
 
     def _get_pages_from_subsitemap(