diff --git a/swh/loader/core/metadata_fetchers.py b/swh/loader/core/metadata_fetchers.py
index fa1d0d5c8c04a85e4c5531120498c6e835d8a32a..edf47a0cbdff38572e75ba7c5f32becdd5c688e0 100644
--- a/swh/loader/core/metadata_fetchers.py
+++ b/swh/loader/core/metadata_fetchers.py
@@ -28,14 +28,11 @@ class MetadataFetcherProtocol(Protocol):
         credentials: CredentialsType,
         lister_name: str,
         lister_instance_name: str,
-    ):
-        ...
+    ): ...
 
-    def get_origin_metadata(self) -> List[RawExtrinsicMetadata]:
-        ...
+    def get_origin_metadata(self) -> List[RawExtrinsicMetadata]: ...
 
-    def get_parent_origins(self) -> List[Origin]:
-        ...
+    def get_parent_origins(self) -> List[Origin]: ...
 
 
 @functools.lru_cache()
diff --git a/swh/loader/core/nar.py b/swh/loader/core/nar.py
index 1cdf97a94e20082d68a96d42096141a7a457e55f..451e3af5179d62be66a41ffc7e0921c152d9a1ff 100644
--- a/swh/loader/core/nar.py
+++ b/swh/loader/core/nar.py
@@ -103,9 +103,9 @@ class Nar:
     ):
         self.hash_names = hash_names
         self.updater = {
-            hash_name: hashlib.sha256()
-            if hash_name.lower() == "sha256"
-            else hashlib.sha1()
+            hash_name: (
+                hashlib.sha256() if hash_name.lower() == "sha256" else hashlib.sha1()
+            )
             for hash_name in hash_names
         }
         format_output = format_output.lower()