diff --git a/swh/loader/package/pypi.py b/swh/loader/package/pypi.py
--- a/swh/loader/package/pypi.py
+++ b/swh/loader/package/pypi.py
@@ -4,6 +4,7 @@
 # See top-level LICENSE file for more information
 
 import os
+import logging
 
 from typing import Any, Dict, Generator, Mapping, Optional, Sequence, Tuple
 from urllib.parse import urlparse
@@ -15,6 +16,8 @@
 from swh.loader.package.loader import PackageLoader
 from swh.loader.package.utils import api_info, release_name
 
+logger = logging.getLogger(__name__)
+
 
 class PyPILoader(PackageLoader):
     """Load pypi origin's artifact releases into swh archive.
@@ -66,12 +69,7 @@
     def resolve_revision_from(
             self, known_artifacts: Dict, artifact_metadata: Dict) \
             -> Optional[bytes]:
-        sha256 = artifact_metadata['digests']['sha256']
-        for rev_id, known_artifact in known_artifacts.items():
-            for original_artifact in known_artifact['original_artifact']:
-                if sha256 == original_artifact['checksums']['sha256']:
-                    return rev_id
-        return None
+        return artifact_to_revision_id(known_artifacts, artifact_metadata)
 
     def build_revision(
             self, a_metadata: Dict, uncompressed_path: str) -> Dict:
@@ -109,6 +107,54 @@
         }
 
 
+def artifact_to_revision_id(
+        known_artifacts: Dict, artifact_metadata: Dict) -> Optional[bytes]:
+    """Given metadata artifact, solves the associated revision id.
+
+    The following code allows to deal with 2 metadata formats (column metadata
+    in 'revision')
+
+    - old format sample:
+
+        {
+            'original_artifact': {
+                'sha256': "6975816f2c5ad4046acc676ba112f2fff945b01522d63948531f11f11e0892ec",  # noqa
+                ...
+            },
+            ...
+        }
+
+    - new format sample:
+
+        {
+            'original_artifact': [{
+                'checksums': {
+                    'sha256': "6975816f2c5ad4046acc676ba112f2fff945b01522d63948531f11f11e0892ec",  # noqa
+                    ...
+                },
+            }],
+            ...
+        }
+
+    """
+    sha256 = artifact_metadata['digests']['sha256']
+    for rev_id, known_artifact in known_artifacts.items():
+        original_artifact = known_artifact['original_artifact']
+        if isinstance(original_artifact, dict):
+            # previous loader-pypi version stored metadata as dict
+            original_sha256 = original_artifact['sha256']
+            if sha256 == original_sha256:
+                return rev_id
+            continue
+        # new pypi loader actually store metadata dict differently...
+        assert isinstance(original_artifact, list)
+        # current loader-pypi stores metadata as list of dict
+        for original_artifact in known_artifact['original_artifact']:
+            if sha256 == original_artifact['checksums']['sha256']:
+                return rev_id
+    return None
+
+
 def pypi_api_url(url: str) -> str:
     """Compute api url from a project url
 
diff --git a/swh/loader/package/tests/test_pypi.py b/swh/loader/package/tests/test_pypi.py
--- a/swh/loader/package/tests/test_pypi.py
+++ b/swh/loader/package/tests/test_pypi.py
@@ -16,7 +16,8 @@
 from swh.model.hashutil import hash_to_bytes
 
 from swh.loader.package.pypi import (
-    PyPILoader, pypi_api_url, author, extract_intrinsic_metadata
+    PyPILoader, pypi_api_url, author, extract_intrinsic_metadata,
+    artifact_to_revision_id
 )
 from swh.loader.package.tests.common import (
     check_snapshot, check_metadata_paths, get_stats
@@ -705,3 +706,98 @@
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'full'
     assert origin_visit['type'] == 'pypi'
+
+
+def test_pypi_artifact_to_revision_id_none():
+    """Current loader version should stop soon if nothing can be found
+
+    """
+    artifact_metadata = {
+        'digests': {
+            'sha256': '6975816f2c5ad4046acc676ba112f2fff945b01522d63948531f11f11e0892ec',  # noqa
+        },
+    }
+
+    assert artifact_to_revision_id({}, artifact_metadata) is None
+
+    known_artifacts = {
+        'b11ebac8c9d0c9e5063a2df693a18e3aba4b2f92': {
+            'original_artifact': {
+                'sha256': 'something-irrelevant',
+            },
+        },
+    }
+
+    assert artifact_to_revision_id(known_artifacts, artifact_metadata) is None
+
+
+def test_pypi_artifact_to_revision_id_old_loader_version():
+    """Current loader version should solve old metadata scheme
+
+    """
+    artifact_metadata = {
+        'digests': {
+            'sha256': '6975816f2c5ad4046acc676ba112f2fff945b01522d63948531f11f11e0892ec',  # noqa
+        }
+    }
+
+    known_artifacts = {
+        hash_to_bytes('b11ebac8c9d0c9e5063a2df693a18e3aba4b2f92'): {
+            'original_artifact': {
+                'sha256': "something-wrong",
+             },
+        },
+        hash_to_bytes('845673bfe8cbd31b1eaf757745a964137e6f9116'): {
+            'original_artifact': {
+                'sha256': '6975816f2c5ad4046acc676ba112f2fff945b01522d63948531f11f11e0892ec',  # noqa
+             },
+        }
+    }
+
+    assert artifact_to_revision_id(known_artifacts, artifact_metadata) \
+        == hash_to_bytes('845673bfe8cbd31b1eaf757745a964137e6f9116')
+
+
+def test_pypi_artifact_to_revision_id_current_loader_version():
+    """Current loader version should be able to solve current metadata scheme
+
+    """
+    artifact_metadata = {
+        'digests': {
+            'sha256': '6975816f2c5ad4046acc676ba112f2fff945b01522d63948531f11f11e0892ec', # noqa
+        }
+    }
+
+    known_artifacts = {
+        hash_to_bytes('b11ebac8c9d0c9e5063a2df693a18e3aba4b2f92'): {
+            'original_artifact': [{
+                'checksums': {
+                    'sha256': '6975816f2c5ad4046acc676ba112f2fff945b01522d63948531f11f11e0892ec',  # noqa
+                },
+            }],
+        },
+        hash_to_bytes('845673bfe8cbd31b1eaf757745a964137e6f9116'): {
+            'original_artifact': [{
+                'checksums': {
+                    'sha256': 'something-wrong'
+                },
+            }],
+        },
+    }
+
+    assert artifact_to_revision_id(known_artifacts, artifact_metadata) \
+        == hash_to_bytes('b11ebac8c9d0c9e5063a2df693a18e3aba4b2f92')
+
+
+def test_pypi_artifact_to_revision_id_failures():
+    with pytest.raises(KeyError, match='sha256'):
+        artifact_metadata = {
+            'digests': {},
+        }
+        assert artifact_to_revision_id({}, artifact_metadata)
+
+    with pytest.raises(KeyError, match='digests'):
+        artifact_metadata = {
+            'something': 'wrong',
+        }
+        assert artifact_to_revision_id({}, artifact_metadata)