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
@@ -485,10 +485,10 @@
 
             ret_ref['target'] = hashutil.bytehex_to_hash(ret_ref['target'])
 
-            branches[ref] = SnapshotBranch(
+            branches[ref] = SnapshotBranch.from_dict(dict(
                 target_type=ret_ref['target_type'],
                 target=ret_ref['target'],
-            )
+            ))
 
         for ref, target in self.symbolic_refs.items():
             branches[ref] = SnapshotBranch(