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
@@ -14,8 +14,7 @@
 from confluent_kafka import Consumer, KafkaException, Producer
 from confluent_kafka.admin import AdminClient
 
-from swh.model.hashutil import hash_to_hex
-from swh.journal.serializers import object_key, kafka_to_key, kafka_to_value
+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
 
 
@@ -84,8 +83,8 @@
 
         for key in known_keys:
             assert key in received_keys, (
-                f"expected {object_type} key {hash_to_hex(key)} "
-                "absent from consumed messages"
+                f"expected {object_type} key {pprint_key(key)} absent from"
+                " consumed messages"
             )
 
         if exclude and object_type in exclude: