diff --git a/swh/journal/replay.py b/swh/journal/replay.py
--- a/swh/journal/replay.py
+++ b/swh/journal/replay.py
@@ -313,18 +313,20 @@
 
 
 def copy_object(obj_id, src, dst):
+    hex_obj_id = hash_to_hex(obj_id)
     obj = ''
     try:
         with statsd.timed(CONTENT_DURATION_METRIC, tags={'request': 'get'}):
             obj = src.get(obj_id)
-            logger.debug('retrieved %s', hash_to_hex(obj_id))
+            logger.debug('retrieved %(obj_id)s', {'obj_id': hex_obj_id})
 
         with statsd.timed(CONTENT_DURATION_METRIC, tags={'request': 'put'}):
             dst.add(obj, obj_id=obj_id, check_presence=False)
-            logger.debug('copied %s', hash_to_hex(obj_id))
+            logger.debug('copied %(obj_id)s', {'obj_id': hex_obj_id})
         statsd.increment(CONTENT_BYTES_METRIC, len(obj))
     except Exception as exc:
-        logger.error('Failed to copy %s: %s', hash_to_hex(obj_id), exc)
+        logger.error('Failed to copy %(obj_id)s: %(exc)s',
+                     {'obj_id': hex_obj_id, 'exc': str(exc)})
         raise
     return len(obj)
 
diff --git a/swh/journal/tests/test_cli.py b/swh/journal/tests/test_cli.py
--- a/swh/journal/tests/test_cli.py
+++ b/swh/journal/tests/test_cli.py
@@ -194,6 +194,46 @@
         assert objstorages['dst'].get(sha1) == content
 
 
+@_patch_objstorages(['src', 'dst'])
+def test_replay_content_structured_log(
+        objstorages,
+        storage,
+        kafka_prefix: str,
+        kafka_consumer_group: str,
+        kafka_server: Tuple[Popen, int],
+        caplog):
+    (_, kafka_port) = kafka_server
+    kafka_prefix += '.swh.journal.objects'
+
+    contents = _fill_objstorage_and_kafka(
+        kafka_port, kafka_prefix, objstorages)
+
+    caplog.set_level(logging.DEBUG, 'swh.journal.replay')
+
+    expected_obj_ids = set(hash_to_hex(sha1) for sha1 in contents)
+
+    result = invoke(False, [
+        'content-replay',
+        '--broker', '127.0.0.1:%d' % kafka_port,
+        '--group-id', kafka_consumer_group,
+        '--prefix', kafka_prefix,
+        '--max-messages', str(NUM_CONTENTS),
+    ])
+    expected = r'Done.\n'
+    assert result.exit_code == 0, result.output
+    assert re.fullmatch(expected, result.output, re.MULTILINE), result.output
+
+    copied = set()
+    for record in caplog.records:
+        logtext = record.getMessage()
+        if 'copied' in logtext:
+            copied.add(record.args['obj_id'])
+
+    assert copied == expected_obj_ids, (
+        "Mismatched logging; see captured log output for details."
+    )
+
+
 @_patch_objstorages(['src', 'dst'])
 def test_replay_content_static_group_id(
         objstorages,
@@ -436,7 +476,7 @@
     assert re.fullmatch(expected, result.output, re.MULTILINE), result.output
 
     copied = 0
-    not_in_src = 0
+    not_in_src = set()
     for record in caplog.records:
         logtext = record.getMessage()
         if 'copied' in logtext:
@@ -444,12 +484,14 @@
         elif 'object not found' in logtext:
             # Check that the object id can be recovered from logs
             assert record.levelno == logging.ERROR
-            assert record.args[0] in contents_deleted
-            not_in_src += 1
+            not_in_src.add(record.args['obj_id'])
 
-    assert (copied == NUM_CONTENTS - num_contents_deleted
-            and not_in_src == num_contents_deleted), (
-        "Unexpected amount of objects copied, see the captured log for details"
+    assert copied == NUM_CONTENTS - num_contents_deleted, (
+        "Unexpected number of contents copied"
+    )
+
+    assert not_in_src == contents_deleted, (
+        "Mismatch between deleted contents and not_in_src logs"
     )
 
     for (sha1, content) in contents.items():