diff --git a/swh/lister/conda/lister.py b/swh/lister/conda/lister.py
--- a/swh/lister/conda/lister.py
+++ b/swh/lister/conda/lister.py
@@ -61,7 +61,9 @@
                 url=self.url, channel=self.channel, arch=arch
             )
             response = self.http_request(url=repodata_url)
-            packages = json.loads(bz2.decompress(response.content))["packages"]
+            packages: Dict[str, Any] = json.loads(bz2.decompress(response.content))[
+                "packages"
+            ]
             yield (arch, packages)
 
     def get_origins_from_page(self, page: CondaListerPage) -> Iterator[ListedOrigin]:
@@ -70,7 +72,11 @@
         arch, packages = page
 
         for filename, package_metadata in packages.items():
-            artifact = {
+            version_key = (
+                f"{arch}/{package_metadata['version']}-{package_metadata['build']}"
+            )
+
+            artifact: Dict[str, Any] = {
                 "filename": filename,
                 "url": self.ARCHIVE_URL_PATTERN.format(
                     url=self.url,
@@ -78,7 +84,7 @@
                     filename=filename,
                     arch=arch,
                 ),
-                "version": package_metadata["version"],
+                "version": version_key,
                 "checksums": {},
             }
 
@@ -86,9 +92,6 @@
                 if checksum in package_metadata:
                     artifact["checksums"][checksum] = package_metadata[checksum]
 
-            version_key = (
-                f"{arch}/{package_metadata['version']}-{package_metadata['build']}"
-            )
             self.packages[package_metadata["name"]][version_key] = artifact
 
             package_date = None
@@ -113,6 +116,8 @@
                 ),
                 last_update=last_update,
                 extra_loader_arguments={
-                    "artifacts": self.packages[package_metadata["name"]],
+                    "artifacts": [
+                        v for k, v in self.packages[package_metadata["name"]].items()
+                    ],
                 },
             )
diff --git a/swh/lister/conda/tests/test_lister.py b/swh/lister/conda/tests/test_lister.py
--- a/swh/lister/conda/tests/test_lister.py
+++ b/swh/lister/conda/tests/test_lister.py
@@ -35,43 +35,43 @@
     expected_origins = [
         {
             "url": "https://anaconda.org/conda-forge/21cmfast",
-            "artifacts": {
-                "linux-64/3.0.2-py36h1af98f8_1": {
+            "artifacts": [
+                {
                     "url": "https://conda.anaconda.org/conda-forge/linux-64/21cmfast-3.0.2-py36h1af98f8_1.tar.bz2",  # noqa: B950
                     "date": "2020-11-11T16:04:49.658000+00:00",
-                    "version": "3.0.2",
+                    "version": "linux-64/3.0.2-py36h1af98f8_1",
                     "filename": "21cmfast-3.0.2-py36h1af98f8_1.tar.bz2",
                     "checksums": {
                         "md5": "d65ab674acf3b7294ebacaec05fc5b54",
                         "sha256": "1154fceeb5c4ee9bb97d245713ac21eb1910237c724d2b7103747215663273c2",  # noqa: B950
                     },
                 }
-            },
+            ],
         },
         {
             "url": "https://anaconda.org/conda-forge/lifetimes",
-            "artifacts": {
-                "linux-64/0.11.1-py36h9f0ad1d_1": {
+            "artifacts": [
+                {
                     "url": "https://conda.anaconda.org/conda-forge/linux-64/lifetimes-0.11.1-py36h9f0ad1d_1.tar.bz2",  # noqa: B950
                     "date": "2020-07-06T12:19:36.425000+00:00",
-                    "version": "0.11.1",
+                    "version": "linux-64/0.11.1-py36h9f0ad1d_1",
                     "filename": "lifetimes-0.11.1-py36h9f0ad1d_1.tar.bz2",
                     "checksums": {
                         "md5": "faa398f7ba0d60ce44aa6eeded490cee",
                         "sha256": "f82a352dfae8abceeeaa538b220fd9c5e4aa4e59092a6a6cea70b9ec0581ea03",  # noqa: B950
                     },
                 },
-                "linux-64/0.11.1-py36hc560c46_1": {
+                {
                     "url": "https://conda.anaconda.org/conda-forge/linux-64/lifetimes-0.11.1-py36hc560c46_1.tar.bz2",  # noqa: B950
                     "date": "2020-07-06T12:19:37.032000+00:00",
-                    "version": "0.11.1",
+                    "version": "linux-64/0.11.1-py36hc560c46_1",
                     "filename": "lifetimes-0.11.1-py36hc560c46_1.tar.bz2",
                     "checksums": {
                         "md5": "c53a689a4c5948e84211bdfc23e3fe68",
                         "sha256": "76146c2ebd6e3b65928bde53a2585287759d77beba785c0eeb889ee565c0035d",  # noqa: B950
                     },
                 },
-            },
+            ],
         },
     ]