diff --git a/swh/loader/git/loader.py b/swh/loader/git/loader.py
--- a/swh/loader/git/loader.py
+++ b/swh/loader/git/loader.py
@@ -84,7 +84,7 @@
             for branch_name, branch in base_snapshot.branches.items():
                 if not branch or branch.target_type == TargetType.ALIAS:
                     continue
-                local_heads.add(hashutil.hash_to_hex(branch.target).encode())
+                local_heads.add(HexBytes(hashutil.hash_to_bytehex(branch.target)))
 
         self.heads = local_heads
 
diff --git a/swh/loader/git/utils.py b/swh/loader/git/utils.py
--- a/swh/loader/git/utils.py
+++ b/swh/loader/git/utils.py
@@ -104,7 +104,7 @@
 
 def warn_dangling_branches(
     branches: Dict[bytes, Optional[SnapshotBranch]],
-    dangling_branches: Dict[bytes, bytes],
+    dangling_branches: Dict[HexBytes, bytes],
     logger: logging.Logger,
     origin_url: str,
 ) -> None: