diff --git a/swh/lister/debian/lister.py b/swh/lister/debian/lister.py
--- a/swh/lister/debian/lister.py
+++ b/swh/lister/debian/lister.py
@@ -7,6 +7,7 @@
 import bz2
 from collections import defaultdict
 from dataclasses import dataclass, field
+from email.utils import parsedate_to_datetime
 import gzip
 from itertools import product
 import logging
@@ -134,6 +135,10 @@
             response = requests.get(url, stream=True)
             logging.debug("Fetched URL: %s, status code: %s", url, response.status_code)
             if response.status_code == 200:
+                last_modified = response.headers.get("Last-Modified")
+                self.last_sources_update = (
+                    parsedate_to_datetime(last_modified) if last_modified else None
+                )
                 decompressor = decompressors.get(compression)
                 if decompressor:
                     data = decompressor(response.raw).readlines()
@@ -224,6 +229,7 @@
                     url=origin_url,
                     visit_type="deb",
                     extra_loader_arguments={"packages": {}},
+                    last_update=self.last_sources_update,
                 )
                 # origin will be yielded at the end of that method
                 origins_to_send[origin_url] = self.listed_origins[origin_url]
diff --git a/swh/lister/debian/tests/test_lister.py b/swh/lister/debian/tests/test_lister.py
--- a/swh/lister/debian/tests/test_lister.py
+++ b/swh/lister/debian/tests/test_lister.py
@@ -4,6 +4,7 @@
 # See top-level LICENSE file for more information
 
 from collections import defaultdict
+from email.utils import formatdate
 import os
 from pathlib import Path
 from typing import Dict, List, Set, Tuple
@@ -78,7 +79,11 @@
             if compression:
                 requests_mock.get(idx_url, status_code=404)
             else:
-                requests_mock.get(idx_url, text=sources)
+                requests_mock.get(
+                    idx_url,
+                    text=sources,
+                    headers={"Last-Modified": formatdate(usegmt=True)},
+                )
 
         for idx_url, _ in lister.debian_index_urls(suite, _components[1]):
             requests_mock.get(idx_url, status_code=404)
@@ -122,6 +127,7 @@
                     ]
 
                     assert filtered_origins
+                    assert filtered_origins[0].last_update is not None
                     packages = filtered_origins[0].extra_loader_arguments["packages"]
                     # check the version info are available
                     assert package_version_key in packages