diff --git a/devstack/lib/notification.sh b/devstack/lib/notification.sh
index 08aeb5e61..8de615a97 100644
--- a/devstack/lib/notification.sh
+++ b/devstack/lib/notification.sh
@@ -92,7 +92,6 @@ configure_monasca-notification() {
     fi
 
     iniset "${MONASCA_NOTIFICATION_CONF}" kafka url ${SERVICE_HOST}:9092
-    iniset "${MONASCA_NOTIFICATION_CONF}" kafka legacy_kafka_client_enabled false
     iniset "${MONASCA_NOTIFICATION_CONF}" database repo_driver ${dbDriver}
     iniset "${MONASCA_NOTIFICATION_CONF}" email_notifier grafana_url ${SERVICE_HOST}:3000
     iniset "${MONASCA_NOTIFICATION_CONF}" keystone auth_url ${SERVICE_HOST}/identity/v3
diff --git a/devstack/lib/persister.sh b/devstack/lib/persister.sh
index bda8d54e8..2233b7afc 100644
--- a/devstack/lib/persister.sh
+++ b/devstack/lib/persister.sh
@@ -172,7 +172,6 @@ configure_monasca_persister_python() {
     iniset $MONASCA_PERSISTER_CONF DEFAULT debug $ENABLE_DEBUG_LOG_LEVEL
 
     iniset "$MONASCA_PERSISTER_CONF" kafka num_processors 1
-    iniset "$MONASCA_PERSISTER_CONF" kafka legacy_kafka_client_enabled false
 
     iniset "$MONASCA_PERSISTER_CONF" kafka_metrics uri $SERVICE_HOST:9092
     iniset "$MONASCA_PERSISTER_CONF" kafka_metrics group_id 1_metrics
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index 765ebc811..3b5ac4597 100755
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -851,7 +851,6 @@ function configure_monasca_api_python {
         # messaging
         iniset "$MONASCA_API_CONF" messaging driver "monasca_api.common.messaging.kafka_publisher:KafkaPublisher"
         iniset "$MONASCA_API_CONF" kafka uri "$SERVICE_HOST:9092"
-        iniset "$MONASCA_API_CONF" kafka legacy_kafka_client_enabled false
 
         # databases
         iniset "$MONASCA_API_CONF" database connection $dbAlarmUrl
diff --git a/monasca_api/conf/kafka.py b/monasca_api/conf/kafka.py
index 99e9e6433..7d39f3eaf 100644
--- a/monasca_api/conf/kafka.py
+++ b/monasca_api/conf/kafka.py
@@ -59,7 +59,7 @@ kafka_opts = [
     cfg.BoolOpt('drop_data', default=False,
                 help='Specify if received data should be simply dropped. '
                      'This parameter is only for testing purposes. (NOT USED)'),
-    cfg.BoolOpt(name='legacy_kafka_client_enabled', default=True,
+    cfg.BoolOpt(name='legacy_kafka_client_enabled', default=False,
                 required=True, advanced=True,
                 help='Enable legacy Kafka client. When set old version of '
                      'kafka-python library is used. Message format version '
diff --git a/releasenotes/notes/disable-legacy-kafka-client-16dd1ac1894fe7a0.yaml b/releasenotes/notes/disable-legacy-kafka-client-16dd1ac1894fe7a0.yaml
new file mode 100644
index 000000000..c8e4e4de5
--- /dev/null
+++ b/releasenotes/notes/disable-legacy-kafka-client-16dd1ac1894fe7a0.yaml
@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    The default value of ``kafka.legacy_kafka_client_enabled`` has changed
+    from ``True`` to ``False``. The use of new Confluent Kafka client is
+    recommended.