diff --git a/swh/journal/tests/conftest.py b/swh/journal/tests/conftest.py
index 93e8541..6fabcf4 100644
--- a/swh/journal/tests/conftest.py
+++ b/swh/journal/tests/conftest.py
@@ -1,244 +1,247 @@
 # Copyright (C) 2019 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import os
 import pytest
 import logging
 
 from kafka import KafkaProducer, KafkaConsumer
 from subprocess import Popen
 from typing import Tuple, Dict
 
 from pathlib import Path
 from pytest_kafka import (
     make_zookeeper_process, make_kafka_server, constants
 )
 
 from swh.journal.publisher import JournalPublisher
 from swh.model.hashutil import hash_to_bytes
 
 from swh.journal.serializers import kafka_to_key, key_to_kafka, kafka_to_value
 
 
 CONTENTS = [
     {
         'length': 3,
         'sha1': hash_to_bytes(
             '34973274ccef6ab4dfaaf86599792fa9c3fe4689'),
         'sha1_git': b'foo',
         'blake2s256': b'bar',
         'sha256': b'baz',
         'status': 'visible',
     },
 ]
 
 COMMITTER = [
     {
         'id': 1,
         'fullname': 'foo',
     },
     {
         'id': 2,
         'fullname': 'bar',
     }
 ]
 
 REVISIONS = [
     {
         'id': hash_to_bytes('7026b7c1a2af56521e951c01ed20f255fa054238'),
         'message': b'hello',
         'date': {
             'timestamp': {
                 'seconds': 1234567891,
                 'microseconds': 0,
             },
             'offset': 120,
             'negative_utc': None,
         },
         'committer': COMMITTER[0],
         'author':  COMMITTER[0],
         'committer_date': None,
     },
     {
         'id': hash_to_bytes('368a48fe15b7db2383775f97c6b247011b3f14f4'),
         'message': b'hello again',
         'date': {
             'timestamp': {
                 'seconds': 1234567892,
                 'microseconds': 0,
             },
             'offset': 120,
             'negative_utc': None,
         },
         'committer': COMMITTER[1],
         'author':  COMMITTER[1],
         'committer_date': None,
     },
 ]
 
 RELEASES = [
     {
         'id': hash_to_bytes('d81cc0710eb6cf9efd5b920a8453e1e07157b6cd'),
         'name': b'v0.0.1',
         'date': {
             'timestamp': {
                 'seconds': 1234567890,
                 'microseconds': 0,
             },
             'offset': 120,
             'negative_utc': None,
         },
         'author': COMMITTER[0],
     },
 ]
 
 ORIGINS = [
     {
         'url': 'https://somewhere.org/den/fox',
         'type': 'git',
     },
     {
         'url': 'https://overtherainbow.org/fox/den',
         'type': 'svn',
     }
 ]
 
 ORIGIN_VISITS = [
     {
         'date': '2013-05-07T04:20:39.369271+00:00',
     },
     {
         'date': '2018-11-27T17:20:39.000000+00:00',
     }
 ]
 
 # From type to tuple (id, <objects instances to test>)
 OBJECT_TYPE_KEYS = {
     'content': (b'sha1', CONTENTS),
     'revision': (b'id', REVISIONS),
     'release': (b'id', RELEASES),
 }
 
 
 TEST_CONFIG = {
     'temporary_prefix': 'swh.tmp_journal.new',
     'final_prefix': 'swh.journal.objects',
     'consumer_id': 'swh.journal.publisher',
     'publisher_id': 'swh.journal.publisher',
     'object_types': OBJECT_TYPE_KEYS.keys(),
     'max_messages': 1,  # will read 1 message and stops
     'storage': {'cls': 'memory', 'args': {}}
 }
 
 
 class JournalPublisherTest(JournalPublisher):
     """A journal publisher which override the default configuration
        parsing setup.
 
     """
     def _prepare_storage(self, config):
         super()._prepare_storage(config)
         self.storage.content_add({'data': b'42', **c} for c in CONTENTS)
         self.storage.revision_add(REVISIONS)
         self.storage.release_add(RELEASES)
         origins = self.storage.origin_add(ORIGINS)
         origin_visits = []
         for i, ov in enumerate(ORIGIN_VISITS):
             origin_id = origins[i]['id']
             ov = self.storage.origin_visit_add(origin_id, ov['date'])
             origin_visits.append(ov)
             self.origins = origins
             self.origin_visits = origin_visits
 
 
 KAFKA_ROOT = os.environ.get('SWH_KAFKA_ROOT')
 KAFKA_ROOT = KAFKA_ROOT if KAFKA_ROOT else os.path.dirname(__file__) + '/kafka'
 if not os.path.exists(KAFKA_ROOT):
     msg = ('Development error: %s must exist and target an '
            'existing kafka installation' % KAFKA_ROOT)
     raise ValueError(msg)
 
 KAFKA_SCRIPTS = Path(KAFKA_ROOT) / 'bin'
 
 KAFKA_BIN = str(KAFKA_SCRIPTS / 'kafka-server-start.sh')
 ZOOKEEPER_BIN = str(KAFKA_SCRIPTS / 'zookeeper-server-start.sh')
 
 
 # Those defines fixtures
 zookeeper_proc = make_zookeeper_process(ZOOKEEPER_BIN)
+os.environ['KAFKA_LOG4J_OPTS'] = \
+    '-Dlog4j.configuration=file:%s/log4j.properties' % \
+    os.path.dirname(__file__)
 kafka_server = make_kafka_server(KAFKA_BIN, 'zookeeper_proc')
 
 logger = logging.getLogger('kafka')
 logger.setLevel(logging.WARN)
 
 
 @pytest.fixture
 def test_config():
     """Test configuration needed for publisher/producer/consumer
 
     """
     return TEST_CONFIG
 
 
 @pytest.fixture
 def producer_to_publisher(
         kafka_server: Tuple[Popen, int],
         test_config: Dict,
 ) -> KafkaProducer:  # noqa
     """Producer to send message to the publisher's consumer.
 
     """
     _, port = kafka_server
     producer = KafkaProducer(
         bootstrap_servers='localhost:{}'.format(port),
         key_serializer=key_to_kafka,
         value_serializer=key_to_kafka,
         client_id=test_config['consumer_id'],
     )
     return producer
 
 
 @pytest.fixture
 def consumer_from_publisher(kafka_server: Tuple[Popen, int],
                             test_config: Dict) -> KafkaConsumer:
     """Get a connected Kafka consumer.
 
     """
     kafka_topics = ['%s.%s' % (test_config['final_prefix'], object_type)
                     for object_type in test_config['object_types']]
     _, kafka_port = kafka_server
     consumer = KafkaConsumer(
         *kafka_topics,
         bootstrap_servers='localhost:{}'.format(kafka_port),
         consumer_timeout_ms=constants.DEFAULT_CONSUMER_TIMEOUT_MS,
         key_deserializer=kafka_to_key,
         value_deserializer=kafka_to_value,
         auto_offset_reset='earliest',
         enable_auto_commit=True,
         group_id="test-consumer"
     )
 
     # Enforce auto_offset_reset=earliest even if the consumer was created
     # too soon wrt the server.
     while len(consumer.assignment()) == 0:
         consumer.poll(timeout_ms=20)
     consumer.seek_to_beginning()
 
     return consumer
 
 
 @pytest.fixture
 def publisher(kafka_server: Tuple[Popen, int],
               test_config: Dict) -> JournalPublisher:
     """Test Publisher factory. We cannot use a fixture here as we need to
        modify the sample.
 
     """
     # consumer and producer of the publisher needs to discuss with the
     # right instance
     _, port = kafka_server
     test_config['brokers'] = ['localhost:{}'.format(port)]
     publisher = JournalPublisherTest(test_config)
     return publisher
diff --git a/swh/journal/tests/log4j.properties b/swh/journal/tests/log4j.properties
new file mode 100644
index 0000000..cce181c
--- /dev/null
+++ b/swh/journal/tests/log4j.properties
@@ -0,0 +1,14 @@
+# Set root logger level to DEBUG and its only appender to A1.
+log4j.rootLogger=DEBUG, A1
+
+# A1 is set to be a ConsoleAppender.
+log4j.appender.A1=org.apache.log4j.ConsoleAppender
+
+# A1 uses PatternLayout.
+log4j.appender.A1.layout=org.apache.log4j.PatternLayout
+log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
+
+log4j.logger.org.apache.log4j=WARN
+log4j.logger.org.apache.kafka=WARN
+log4j.logger.kafka=WARN
+log4j.logger.org.apache.zookeeper=WARN