diff --git a/swh/lister/bioconductor/lister.py b/swh/lister/bioconductor/lister.py
index 95895cd..e050f76 100644
--- a/swh/lister/bioconductor/lister.py
+++ b/swh/lister/bioconductor/lister.py
@@ -127,6 +127,7 @@ class BioconductorLister(Lister[BioconductorListerState, BioconductorListerPage]
                     packages_txt = self.http_request(url).text
                     packages = self.parse_packages(packages_txt)
                 except HTTPError as e:
+                    assert e.response is not None
                     logger.debug(
                         "Skipping page since got %s response for %s",
                         e.response.status_code,
diff --git a/swh/lister/bitbucket/lister.py b/swh/lister/bitbucket/lister.py
index 00d8abf..f129bc0 100644
--- a/swh/lister/bitbucket/lister.py
+++ b/swh/lister/bitbucket/lister.py
@@ -125,7 +125,7 @@ class BitbucketLister(Lister[BitbucketListerState, List[Dict[str, Any]]]):
                 body = self.http_request(self.url, params=self.url_params).json()
                 yield body["values"]
             except HTTPError as e:
-                if e.response.status_code == 500:
+                if e.response is not None and e.response.status_code == 500:
                     logger.warning(
                         "URL %s is buggy (error 500), skip it and get next page.",
                         e.response.url,
diff --git a/swh/lister/cgit/lister.py b/swh/lister/cgit/lister.py
index 1ab17cb..af3d703 100644
--- a/swh/lister/cgit/lister.py
+++ b/swh/lister/cgit/lister.py
@@ -160,6 +160,7 @@ class CGitLister(StatelessLister[Repositories]):
         try:
             bs = self._get_and_parse(repository_url)
         except HTTPError as e:
+            assert e.response is not None
             logger.warning(
                 "Unexpected HTTP status code %s on %s",
                 e.response.status_code,
diff --git a/swh/lister/gitlab/lister.py b/swh/lister/gitlab/lister.py
index d2b1bd5..e7c3fb5 100644
--- a/swh/lister/gitlab/lister.py
+++ b/swh/lister/gitlab/lister.py
@@ -56,6 +56,7 @@ def _if_rate_limited(retry_state) -> bool:
         exc = attempt.exception()
         return (
             isinstance(exc, HTTPError)
+            and exc.response is not None
             and exc.response.status_code == codes.forbidden
             and int(exc.response.headers.get("RateLimit-Remaining", "0")) == 0
         ) or is_retryable_exception(exc)
diff --git a/swh/lister/gitweb/lister.py b/swh/lister/gitweb/lister.py
index 86720c3..2652114 100644
--- a/swh/lister/gitweb/lister.py
+++ b/swh/lister/gitweb/lister.py
@@ -125,6 +125,7 @@ class GitwebLister(StatelessLister[Repositories]):
         try:
             bs = self._get_and_parse(repository_url)
         except HTTPError as e:
+            assert e.response is not None
             logger.warning(
                 "Unexpected HTTP status code %s on %s",
                 e.response.status_code,
diff --git a/swh/lister/gogs/lister.py b/swh/lister/gogs/lister.py
index b9db3d3..0d1547c 100644
--- a/swh/lister/gogs/lister.py
+++ b/swh/lister/gogs/lister.py
@@ -135,7 +135,8 @@ class GogsLister(Lister[GogsListerState, GogsListerPage]):
             response = self.http_request(url, params=params)
         except HTTPError as http_error:
             if (
-                http_error.response.status_code == 500
+                http_error.response is not None
+                and http_error.response.status_code == 500
             ):  # Temporary hack for skipping fatal repos (T4423)
                 url_parts = urlparse(url)
                 query: Dict[str, Any] = dict(parse_qsl(url_parts.query))
diff --git a/swh/lister/stagit/lister.py b/swh/lister/stagit/lister.py
index b87ca66..7a2187f 100644
--- a/swh/lister/stagit/lister.py
+++ b/swh/lister/stagit/lister.py
@@ -113,6 +113,7 @@ class StagitLister(StatelessLister[Repositories]):
         try:
             bs = self._get_and_parse(repository_url)
         except HTTPError as e:
+            assert e.response is not None
             logger.warning(
                 "Unexpected HTTP status code %s on %s",
                 e.response.status_code,