diff --git a/requirements-swh.txt b/requirements-swh.txt
--- a/requirements-swh.txt
+++ b/requirements-swh.txt
@@ -1,5 +1,5 @@
 swh.core >= 0.0.7
 swh.loader.core >= 0.0.78
-swh.model >= 0.0.60
+swh.model >= 0.3.0
 swh.scheduler >= 0.0.39
 swh.storage >= 0.0.108
diff --git a/swh/loader/git/converters.py b/swh/loader/git/converters.py
--- a/swh/loader/git/converters.py
+++ b/swh/loader/git/converters.py
@@ -79,7 +79,7 @@
             )
         )
 
-    return Directory(id=tree.sha().digest(), entries=entries,)
+    return Directory(id=tree.sha().digest(), entries=tuple(entries),)
 
 
 def parse_author(name_email: bytes) -> Person:
@@ -140,7 +140,7 @@
         message=commit.message,
         metadata=metadata,
         synthetic=False,
-        parents=[bytes.fromhex(p.decode()) for p in commit.parents],
+        parents=tuple(bytes.fromhex(p.decode()) for p in commit.parents),
     )
 
 
diff --git a/swh/loader/git/tests/test_converters.py b/swh/loader/git/tests/test_converters.py
--- a/swh/loader/git/tests/test_converters.py
+++ b/swh/loader/git/tests/test_converters.py
@@ -169,7 +169,7 @@
                 negative_utc=False,
                 offset=120,
             ),
-            parents=[b"\xc3\xc5\x88q23`\x9f[\xbb\xb2\xd9\xe7\xf3\xfbJf\x0f?r"],
+            parents=(b"\xc3\xc5\x88q23`\x9f[\xbb\xb2\xd9\xe7\xf3\xfbJf\x0f?r",),
             synthetic=False,
         )