diff --git a/swh/journal/pytest_plugin.py b/swh/journal/pytest_plugin.py
--- a/swh/journal/pytest_plugin.py
+++ b/swh/journal/pytest_plugin.py
@@ -9,13 +9,18 @@
 from typing import Collection, Dict, Iterator, Optional
 from collections import defaultdict
 
+import attr
 import pytest
 
 from confluent_kafka import Consumer, KafkaException, Producer
 from confluent_kafka.admin import AdminClient
 
 from swh.journal.serializers import object_key, kafka_to_key, kafka_to_value, pprint_key
-from swh.journal.tests.journal_data import TEST_OBJECTS, TEST_OBJECT_DICTS
+from swh.journal.tests.journal_data import (
+    TEST_OBJECTS,
+    TEST_OBJECT_DICTS,
+    MODEL_OBJECTS,
+)
 
 
 def consume_messages(consumer, kafka_prefix, expected_messages):
@@ -63,14 +68,14 @@
 def assert_all_objects_consumed(
     consumed_messages: Dict, exclude: Optional[Collection] = None
 ):
-    """Check whether all objects from TEST_OBJECT_DICTS have been consumed
+    """Check whether all objects from TEST_OBJECTS have been consumed
 
     `exclude` can be a list of object types for which we do not want to compare the
     values (eg. for anonymized object).
 
     """
-    for object_type, known_values in TEST_OBJECT_DICTS.items():
-        known_keys = [object_key(object_type, obj) for obj in TEST_OBJECTS[object_type]]
+    for object_type, known_objects in TEST_OBJECTS.items():
+        known_keys = [object_key(object_type, obj) for obj in known_objects]
 
         if not consumed_messages[object_type]:
             return
@@ -80,6 +85,8 @@
         if object_type in ("content", "skipped_content"):
             for value in received_values:
                 del value["ctime"]
+        if object_type == "content":
+            known_objects = [attr.evolve(o, data=None) for o in known_objects]
 
         for key in known_keys:
             assert key in received_keys, (
@@ -90,8 +97,12 @@
         if exclude and object_type in exclude:
             continue
 
-        for value in known_values:
-            assert value in received_values, (
+        received_objects = [
+            MODEL_OBJECTS[object_type].from_dict(d) for d in received_values
+        ]
+
+        for value in known_objects:
+            assert value in received_objects, (
                 f"expected {object_type} value {value!r} is "
                 "absent from consumed messages"
             )
diff --git a/swh/journal/tests/journal_data.py b/swh/journal/tests/journal_data.py
--- a/swh/journal/tests/journal_data.py
+++ b/swh/journal/tests/journal_data.py
@@ -23,17 +23,23 @@
     Snapshot,
 )
 
+MODEL_CLASSES = (
+    Content,
+    Directory,
+    Origin,
+    OriginVisit,
+    OriginVisitStatus,
+    Release,
+    Revision,
+    SkippedContent,
+    Snapshot,
+)
 
 OBJECT_TYPES: Dict[Type[BaseModel], str] = {
-    Content: "content",
-    Directory: "directory",
-    Origin: "origin",
-    OriginVisit: "origin_visit",
-    OriginVisitStatus: "origin_visit_status",
-    Release: "release",
-    Revision: "revision",
-    SkippedContent: "skipped_content",
-    Snapshot: "snapshot",
+    cls: cls.object_type for cls in MODEL_CLASSES  # type: ignore
+}
+MODEL_OBJECTS: Dict[str, Type[BaseModel]] = {
+    cls.object_type: cls for cls in MODEL_CLASSES  # type: ignore
 }
 
 UTC = datetime.timezone.utc
@@ -42,6 +48,7 @@
     {
         **MultiHash.from_data(f"foo{i}".encode()).digest(),
         "length": 4,
+        "data": f"foo{i}".encode(),
         "status": "visible",
     }
     for i in range(10)
@@ -49,6 +56,7 @@
     {
         **MultiHash.from_data(f"forbidden foo{i}".encode()).digest(),
         "length": 14,
+        "data": f"forbidden foo{i}".encode(),
         "status": "hidden",
     }
     for i in range(10)
@@ -302,8 +310,6 @@
     "skipped_content": SKIPPED_CONTENTS,
 }
 
-MODEL_OBJECTS = {v: k for (k, v) in OBJECT_TYPES.items()}
-
 TEST_OBJECTS: Dict[str, List[ModelObject]] = {}
 
 for object_type, objects in TEST_OBJECT_DICTS.items():
@@ -312,7 +318,7 @@
 
     for (num, obj_d) in enumerate(objects):
         if object_type == "content":
-            obj_d = {**obj_d, "data": b"", "ctime": datetime.datetime.now(tz=UTC)}
+            obj_d = {**obj_d, "ctime": datetime.datetime.now(tz=UTC)}
 
         converted_objects.append(model.from_dict(obj_d))