diff --git a/swh/journal/tests/test_kafka_writer.py b/swh/journal/tests/test_kafka_writer.py
--- a/swh/journal/tests/test_kafka_writer.py
+++ b/swh/journal/tests/test_kafka_writer.py
@@ -49,6 +49,9 @@
             )
     for key, obj_dict in consumed_messages["release"]:
         obj = Release.from_dict(obj_dict)
+        # author is optional for release
+        if obj.author is None:
+            continue
         for person in (obj.author,):
             assert not (
                 len(person.fullname) == 32
@@ -92,6 +95,9 @@
             )
     for key, obj_dict in consumed_messages["release"]:
         obj = Release.from_dict(obj_dict)
+        # author is optional for release
+        if obj.author is None:
+            continue
         for person in (obj.author,):
             assert (
                 len(person.fullname) == 32