diff --git a/requirements-swh.txt b/requirements-swh.txt
--- a/requirements-swh.txt
+++ b/requirements-swh.txt
@@ -1,4 +1,4 @@
 swh.core >= 0.0.75
 swh.model >= 0.0.60
 swh.scheduler
-swh.storage >= 0.0.178
+swh.storage >= 0.0.183
diff --git a/swh/loader/package/loader.py b/swh/loader/package/loader.py
--- a/swh/loader/package/loader.py
+++ b/swh/loader/package/loader.py
@@ -29,6 +29,7 @@
     Origin,
 )
 from swh.storage import get_storage
+from swh.storage.exc import HashCollision
 from swh.storage.algos.snapshot import snapshot_get_all_branches
 
 from swh.loader.package.utils import download
@@ -318,7 +319,7 @@
             status_load = "failed"
             return finalize_visit()
 
-        load_exceptions = []
+        load_exceptions: List[Exception] = []
 
         for version in self.get_versions():  # for each
             logger.debug("version: %s", version)
@@ -331,6 +332,13 @@
                     try:
                         revision_id = self._load_revision(p_info, origin)
                         status_load = "eventful"
+                    except HashCollision as e:
+                        self.storage.clear_buffers()
+                        load_exceptions.append(e)
+                        sentry_sdk.capture_exception(e)
+                        logger.exception('Failed loading branch %s for %s',
+                                         branch_name, self.url)
+                        continue
                     except Exception as e:
                         load_exceptions.append(e)
                         sentry_sdk.capture_exception(e)
diff --git a/swh/loader/package/nixguix/tests/test_nixguix.py b/swh/loader/package/nixguix/tests/test_nixguix.py
--- a/swh/loader/package/nixguix/tests/test_nixguix.py
+++ b/swh/loader/package/nixguix/tests/test_nixguix.py
@@ -4,6 +4,9 @@
 # See top-level LICENSE file for more information
 
 import pytest
+
+from typing import Dict, Optional, Tuple
+
 from json.decoder import JSONDecodeError
 
 from swh.loader.package.nixguix.loader import (
@@ -12,7 +15,11 @@
     clean_sources,
 )
 
-from swh.loader.package.tests.common import get_stats, check_snapshot
+from swh.loader.package.tests.common import (
+    get_stats, check_snapshot
+)
+from swh.loader.package.utils import download
+from swh.storage.exc import HashCollision
 
 sources_url = "https://nix-community.github.io/nixpkgs-swh/sources.json"
 
@@ -302,3 +309,58 @@
     }
 
     check_snapshot(expected_snapshot, storage=loader.storage)
+
+
+def fake_download(url: str, dest: str, hashes: Dict = {},
+                  filename: Optional[str] = None,
+                  auth: Optional[Tuple[str, str]] = None) -> Tuple[str, Dict]:
+    """Fake download which raises HashCollision
+
+    For tests only.
+
+    """
+    if url == 'https://example.com/file.txt':
+        # instead of failing because it's a file not dealt with by the nix guix
+        # loader, make it raise a hash collision
+        raise HashCollision(
+            'sha1', 'f92d74e3874587aaf443d1db961d4e26dde13e9c', [])
+    return download(url, dest, hashes, filename, auth)
+
+
+def test_raise_hash_collision(swh_config, requests_mock_datadir, mocker):
+    mock_download = mocker.patch('swh.loader.package.loader.download')
+    mock_download.side_effect = fake_download
+
+    loader = NixGuixLoader(sources_url)
+    res = loader.load()
+
+    expected_snapshot_id = '0c5881c74283793ebe9a09a105a9381e41380383'
+    assert res == {
+        'status': 'eventful',
+        'snapshot_id': expected_snapshot_id,
+    }
+
+    expected_branches = {
+        'https://github.com/owner-1/repository-1/revision-1.tgz': {
+            'target': '488ad4e7b8e2511258725063cf43a2b897c503b4',
+            'target_type': 'revision',
+        },
+        'evaluation': {
+            'target': 'cc4e04c26672dd74e5fd0fecb78b435fb55368f7',
+            'target_type': 'revision',
+        },
+    }
+    expected_snapshot = {
+        'id': expected_snapshot_id,
+        'branches': expected_branches,
+    }
+
+    check_snapshot(expected_snapshot, storage=loader.storage)
+
+    assert len(mock_download.mock_calls) == 2
+
+    origin_visit = loader.storage.origin_visit_get_latest(sources_url)
+
+    # The visit is partial because some hash collision were detected
+    assert origin_visit['status'] == 'partial'
+    assert origin_visit['type'] == 'nixguix'