diff --git a/apps/emqx/src/emqx_limiter/src/emqx_limiter_schema.erl b/apps/emqx/src/emqx_limiter/src/emqx_limiter_schema.erl
index fa67e1977..ddfc55f7a 100644
--- a/apps/emqx/src/emqx_limiter/src/emqx_limiter_schema.erl
+++ b/apps/emqx/src/emqx_limiter/src/emqx_limiter_schema.erl
@@ -110,11 +110,11 @@ fields(limiter) ->
         ];
 fields(node_opts) ->
     [
-        {rate, ?HOCON(rate(), #{desc => ?DESC(rate), default => "infinity"})},
+        {rate, ?HOCON(rate(), #{desc => ?DESC(rate), default => <<"infinity">>})},
         {burst,
             ?HOCON(burst_rate(), #{
                 desc => ?DESC(burst),
-                default => 0
+                default => <<"0">>
             })}
     ];
 fields(client_fields) ->
@@ -128,14 +128,14 @@ fields(client_fields) ->
     ];
 fields(bucket_opts) ->
     [
-        {rate, ?HOCON(rate(), #{desc => ?DESC(rate), default => "infinity"})},
-        {capacity, ?HOCON(capacity(), #{desc => ?DESC(capacity), default => "infinity"})},
-        {initial, ?HOCON(initial(), #{default => "0", desc => ?DESC(initial)})}
+        {rate, ?HOCON(rate(), #{desc => ?DESC(rate), default => <<"infinity">>})},
+        {capacity, ?HOCON(capacity(), #{desc => ?DESC(capacity), default => <<"infinity">>})},
+        {initial, ?HOCON(initial(), #{default => <<"0">>, desc => ?DESC(initial)})}
     ];
 fields(client_opts) ->
     [
-        {rate, ?HOCON(rate(), #{default => "infinity", desc => ?DESC(rate)})},
-        {initial, ?HOCON(initial(), #{default => "0", desc => ?DESC(initial)})},
+        {rate, ?HOCON(rate(), #{default => <<"infinity">>, desc => ?DESC(rate)})},
+        {initial, ?HOCON(initial(), #{default => <<"0">>, desc => ?DESC(initial)})},
         %% low_watermark add for emqx_channel and emqx_session
         %% both modules consume first and then check
         %% so we need to use this value to prevent excessive consumption
@@ -145,13 +145,13 @@ fields(client_opts) ->
                 initial(),
                 #{
                     desc => ?DESC(low_watermark),
-                    default => "0"
+                    default => <<"0">>
                 }
             )},
         {capacity,
             ?HOCON(capacity(), #{
                 desc => ?DESC(client_bucket_capacity),
-                default => "infinity"
+                default => <<"infinity">>
             })},
         {divisible,
             ?HOCON(
@@ -166,7 +166,7 @@ fields(client_opts) ->
                 emqx_schema:duration(),
                 #{
                     desc => ?DESC(max_retry_time),
-                    default => "10s"
+                    default => <<"10s">>
                 }
             )},
         {failure_strategy,
diff --git a/apps/emqx/src/emqx_schema.erl b/apps/emqx/src/emqx_schema.erl
index 008aa23c9..8d24e6937 100644
--- a/apps/emqx/src/emqx_schema.erl
+++ b/apps/emqx/src/emqx_schema.erl
@@ -268,7 +268,7 @@ fields("persistent_session_store") ->
             sc(
                 duration(),
                 #{
-                    default => "1h",
+                    default => <<"1h">>,
                     desc => ?DESC(persistent_session_store_max_retain_undelivered)
                 }
             )},
@@ -276,7 +276,7 @@ fields("persistent_session_store") ->
             sc(
                 duration(),
                 #{
-                    default => "1h",
+                    default => <<"1h">>,
                     desc => ?DESC(persistent_session_store_message_gc_interval)
                 }
             )},
@@ -284,7 +284,7 @@ fields("persistent_session_store") ->
             sc(
                 duration(),
                 #{
-                    default => "1m",
+                    default => <<"1m">>,
                     desc => ?DESC(persistent_session_store_session_message_gc_interval)
                 }
             )}
@@ -352,7 +352,7 @@ fields("authz_cache") ->
             sc(
                 duration(),
                 #{
-                    default => "1m",
+                    default => <<"1m">>,
                     desc => ?DESC(fields_cache_ttl)
                 }
             )}
@@ -363,7 +363,7 @@ fields("mqtt") ->
             sc(
                 hoconsc:union([infinity, duration()]),
                 #{
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC(mqtt_idle_timeout)
                 }
             )},
@@ -371,7 +371,7 @@ fields("mqtt") ->
             sc(
                 bytesize(),
                 #{
-                    default => "1MB",
+                    default => <<"1MB">>,
                     desc => ?DESC(mqtt_max_packet_size)
                 }
             )},
@@ -507,7 +507,7 @@ fields("mqtt") ->
             sc(
                 duration(),
                 #{
-                    default => "30s",
+                    default => <<"30s">>,
                     desc => ?DESC(mqtt_retry_interval)
                 }
             )},
@@ -523,7 +523,7 @@ fields("mqtt") ->
             sc(
                 duration(),
                 #{
-                    default => "300s",
+                    default => <<"300s">>,
                     desc => ?DESC(mqtt_await_rel_timeout)
                 }
             )},
@@ -531,7 +531,7 @@ fields("mqtt") ->
             sc(
                 duration(),
                 #{
-                    default => "2h",
+                    default => <<"2h">>,
                     desc => ?DESC(mqtt_session_expiry_interval)
                 }
             )},
@@ -617,7 +617,7 @@ fields("flapping_detect") ->
             sc(
                 duration(),
                 #{
-                    default => "1m",
+                    default => <<"1m">>,
                     desc => ?DESC(flapping_detect_window_time)
                 }
             )},
@@ -625,7 +625,7 @@ fields("flapping_detect") ->
             sc(
                 duration(),
                 #{
-                    default => "5m",
+                    default => <<"5m">>,
                     desc => ?DESC(flapping_detect_ban_time)
                 }
             )}
@@ -652,7 +652,7 @@ fields("force_shutdown") ->
             sc(
                 wordsize(),
                 #{
-                    default => "32MB",
+                    default => <<"32MB">>,
                     desc => ?DESC(force_shutdown_max_heap_size),
                     validator => fun ?MODULE:validate_heap_size/1
                 }
@@ -715,7 +715,7 @@ fields("conn_congestion") ->
             sc(
                 duration(),
                 #{
-                    default => "1m",
+                    default => <<"1m">>,
                     desc => ?DESC(conn_congestion_min_alarm_sustain_duration)
                 }
             )}
@@ -739,7 +739,7 @@ fields("force_gc") ->
             sc(
                 bytesize(),
                 #{
-                    default => "16MB",
+                    default => <<"16MB">>,
                     desc => ?DESC(force_gc_bytes)
                 }
             )}
@@ -874,7 +874,7 @@ fields("mqtt_quic_listener") ->
             sc(
                 duration_ms(),
                 #{
-                    default => "10s",
+                    default => <<"10s">>,
                     desc => ?DESC(fields_mqtt_quic_listener_handshake_idle_timeout)
                 }
             )},
@@ -901,7 +901,7 @@ fields("ws_opts") ->
             sc(
                 string(),
                 #{
-                    default => "/mqtt",
+                    default => <<"/mqtt">>,
                     desc => ?DESC(fields_ws_opts_mqtt_path)
                 }
             )},
@@ -925,7 +925,7 @@ fields("ws_opts") ->
             sc(
                 duration(),
                 #{
-                    default => "7200s",
+                    default => <<"7200s">>,
                     desc => ?DESC(fields_ws_opts_idle_timeout)
                 }
             )},
@@ -949,7 +949,7 @@ fields("ws_opts") ->
             sc(
                 comma_separated_list(),
                 #{
-                    default => "mqtt, mqtt-v3, mqtt-v3.1.1, mqtt-v5",
+                    default => <<"mqtt, mqtt-v3, mqtt-v3.1.1, mqtt-v5">>,
                     desc => ?DESC(fields_ws_opts_supported_subprotocols)
                 }
             )},
@@ -981,7 +981,7 @@ fields("ws_opts") ->
             sc(
                 string(),
                 #{
-                    default => "x-forwarded-for",
+                    default => <<"x-forwarded-for">>,
                     desc => ?DESC(fields_ws_opts_proxy_address_header)
                 }
             )},
@@ -989,7 +989,7 @@ fields("ws_opts") ->
             sc(
                 string(),
                 #{
-                    default => "x-forwarded-port",
+                    default => <<"x-forwarded-port">>,
                     desc => ?DESC(fields_ws_opts_proxy_port_header)
                 }
             )},
@@ -1021,7 +1021,7 @@ fields("tcp_opts") ->
             sc(
                 duration(),
                 #{
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC(fields_tcp_opts_send_timeout)
                 }
             )},
@@ -1062,7 +1062,7 @@ fields("tcp_opts") ->
             sc(
                 bytesize(),
                 #{
-                    default => "1MB",
+                    default => <<"1MB">>,
                     desc => ?DESC(fields_tcp_opts_high_watermark)
                 }
             )},
@@ -1275,7 +1275,7 @@ fields("sys_topics") ->
             sc(
                 hoconsc:union([disabled, duration()]),
                 #{
-                    default => "1m",
+                    default => <<"1m">>,
                     desc => ?DESC(sys_msg_interval)
                 }
             )},
@@ -1283,7 +1283,7 @@ fields("sys_topics") ->
             sc(
                 hoconsc:union([disabled, duration()]),
                 #{
-                    default => "30s",
+                    default => <<"30s">>,
                     desc => ?DESC(sys_heartbeat_interval)
                 }
             )},
@@ -1352,7 +1352,7 @@ fields("sysmon_vm") ->
             sc(
                 duration(),
                 #{
-                    default => "30s",
+                    default => <<"30s">>,
                     desc => ?DESC(sysmon_vm_process_check_interval)
                 }
             )},
@@ -1360,7 +1360,7 @@ fields("sysmon_vm") ->
             sc(
                 percent(),
                 #{
-                    default => "80%",
+                    default => <<"80%">>,
                     desc => ?DESC(sysmon_vm_process_high_watermark)
                 }
             )},
@@ -1368,7 +1368,7 @@ fields("sysmon_vm") ->
             sc(
                 percent(),
                 #{
-                    default => "60%",
+                    default => <<"60%">>,
                     desc => ?DESC(sysmon_vm_process_low_watermark)
                 }
             )},
@@ -1384,7 +1384,7 @@ fields("sysmon_vm") ->
             sc(
                 hoconsc:union([disabled, duration()]),
                 #{
-                    default => "240ms",
+                    default => <<"240ms">>,
                     desc => ?DESC(sysmon_vm_long_schedule)
                 }
             )},
@@ -1392,7 +1392,7 @@ fields("sysmon_vm") ->
             sc(
                 hoconsc:union([disabled, bytesize()]),
                 #{
-                    default => "32MB",
+                    default => <<"32MB">>,
                     desc => ?DESC(sysmon_vm_large_heap)
                 }
             )},
@@ -1419,7 +1419,7 @@ fields("sysmon_os") ->
             sc(
                 duration(),
                 #{
-                    default => "60s",
+                    default => <<"60s">>,
                     desc => ?DESC(sysmon_os_cpu_check_interval)
                 }
             )},
@@ -1427,7 +1427,7 @@ fields("sysmon_os") ->
             sc(
                 percent(),
                 #{
-                    default => "80%",
+                    default => <<"80%">>,
                     desc => ?DESC(sysmon_os_cpu_high_watermark)
                 }
             )},
@@ -1435,7 +1435,7 @@ fields("sysmon_os") ->
             sc(
                 percent(),
                 #{
-                    default => "60%",
+                    default => <<"60%">>,
                     desc => ?DESC(sysmon_os_cpu_low_watermark)
                 }
             )},
@@ -1443,7 +1443,7 @@ fields("sysmon_os") ->
             sc(
                 hoconsc:union([disabled, duration()]),
                 #{
-                    default => "60s",
+                    default => <<"60s">>,
                     desc => ?DESC(sysmon_os_mem_check_interval)
                 }
             )},
@@ -1451,7 +1451,7 @@ fields("sysmon_os") ->
             sc(
                 percent(),
                 #{
-                    default => "70%",
+                    default => <<"70%">>,
                     desc => ?DESC(sysmon_os_sysmem_high_watermark)
                 }
             )},
@@ -1459,7 +1459,7 @@ fields("sysmon_os") ->
             sc(
                 percent(),
                 #{
-                    default => "5%",
+                    default => <<"5%">>,
                     desc => ?DESC(sysmon_os_procmem_high_watermark)
                 }
             )}
@@ -1480,7 +1480,7 @@ fields("sysmon_top") ->
                 emqx_schema:duration(),
                 #{
                     mapping => "system_monitor.top_sample_interval",
-                    default => "2s",
+                    default => <<"2s">>,
                     desc => ?DESC(sysmon_top_sample_interval)
                 }
             )},
@@ -1499,7 +1499,7 @@ fields("sysmon_top") ->
                 #{
                     mapping => "system_monitor.db_hostname",
                     desc => ?DESC(sysmon_top_db_hostname),
-                    default => ""
+                    default => <<>>
                 }
             )},
         {"db_port",
@@ -1516,7 +1516,7 @@ fields("sysmon_top") ->
                 string(),
                 #{
                     mapping => "system_monitor.db_username",
-                    default => "system_monitor",
+                    default => <<"system_monitor">>,
                     desc => ?DESC(sysmon_top_db_username)
                 }
             )},
@@ -1525,7 +1525,7 @@ fields("sysmon_top") ->
                 binary(),
                 #{
                     mapping => "system_monitor.db_password",
-                    default => "system_monitor_password",
+                    default => <<"system_monitor_password">>,
                     desc => ?DESC(sysmon_top_db_password),
                     converter => fun password_converter/2,
                     sensitive => true
@@ -1536,7 +1536,7 @@ fields("sysmon_top") ->
                 string(),
                 #{
                     mapping => "system_monitor.db_name",
-                    default => "postgres",
+                    default => <<"postgres">>,
                     desc => ?DESC(sysmon_top_db_name)
                 }
             )}
@@ -1566,7 +1566,7 @@ fields("alarm") ->
             sc(
                 duration(),
                 #{
-                    default => "24h",
+                    default => <<"24h">>,
                     example => "24h",
                     desc => ?DESC(alarm_validity_period)
                 }
@@ -1605,7 +1605,7 @@ mqtt_listener(Bind) ->
                     duration(),
                     #{
                         desc => ?DESC(mqtt_listener_proxy_protocol_timeout),
-                        default => "3s"
+                        default => <<"3s">>
                     }
                 )},
             {?EMQX_AUTHENTICATION_CONFIG_ROOT_NAME, authentication(listener)}
@@ -1956,7 +1956,7 @@ common_ssl_opts_schema(Defaults) ->
             sc(
                 duration(),
                 #{
-                    default => Df("hibernate_after", "5s"),
+                    default => Df("hibernate_after", <<"5s">>),
                     desc => ?DESC(common_ssl_opts_schema_hibernate_after)
                 }
             )}
@@ -2006,7 +2006,7 @@ server_ssl_opts_schema(Defaults, IsRanchListener) ->
                 sc(
                     duration(),
                     #{
-                        default => Df("handshake_timeout", "15s"),
+                        default => Df("handshake_timeout", <<"15s">>),
                         desc => ?DESC(server_ssl_opts_schema_handshake_timeout)
                     }
                 )}
diff --git a/apps/emqx_authn/src/emqx_authn.app.src b/apps/emqx_authn/src/emqx_authn.app.src
index 0b5b0dedc..7fbdf787a 100644
--- a/apps/emqx_authn/src/emqx_authn.app.src
+++ b/apps/emqx_authn/src/emqx_authn.app.src
@@ -1,7 +1,7 @@
 %% -*- mode: erlang -*-
 {application, emqx_authn, [
     {description, "EMQX Authentication"},
-    {vsn, "0.1.13"},
+    {vsn, "0.1.14"},
     {modules, []},
     {registered, [emqx_authn_sup, emqx_authn_registry]},
     {applications, [kernel, stdlib, emqx_resource, emqx_connector, ehttpc, epgsql, mysql, jose]},
diff --git a/apps/emqx_authn/src/simple_authn/emqx_authn_mysql.erl b/apps/emqx_authn/src/simple_authn/emqx_authn_mysql.erl
index 0e6eeb6af..bedd169e2 100644
--- a/apps/emqx_authn/src/simple_authn/emqx_authn_mysql.erl
+++ b/apps/emqx_authn/src/simple_authn/emqx_authn_mysql.erl
@@ -74,7 +74,7 @@ query(_) -> undefined.
 
 query_timeout(type) -> emqx_schema:duration_ms();
 query_timeout(desc) -> ?DESC(?FUNCTION_NAME);
-query_timeout(default) -> "5s";
+query_timeout(default) -> <<"5s">>;
 query_timeout(_) -> undefined.
 
 %%------------------------------------------------------------------------------
diff --git a/apps/emqx_authz/src/emqx_authz.app.src b/apps/emqx_authz/src/emqx_authz.app.src
index 3fea50147..f016db09a 100644
--- a/apps/emqx_authz/src/emqx_authz.app.src
+++ b/apps/emqx_authz/src/emqx_authz.app.src
@@ -1,7 +1,7 @@
 %% -*- mode: erlang -*-
 {application, emqx_authz, [
     {description, "An OTP application"},
-    {vsn, "0.1.13"},
+    {vsn, "0.1.14"},
     {registered, []},
     {mod, {emqx_authz_app, []}},
     {applications, [
diff --git a/apps/emqx_authz/src/emqx_authz_api_schema.erl b/apps/emqx_authz/src/emqx_authz_api_schema.erl
index 44ec0d28a..4adada182 100644
--- a/apps/emqx_authz/src/emqx_authz_api_schema.erl
+++ b/apps/emqx_authz/src/emqx_authz_api_schema.erl
@@ -108,7 +108,7 @@ authz_http_common_fields() ->
                 })},
             {request_timeout,
                 mk_duration("Request timeout", #{
-                    required => false, default => "30s", desc => ?DESC(request_timeout)
+                    required => false, default => <<"30s">>, desc => ?DESC(request_timeout)
                 })}
         ] ++
         maps:to_list(
diff --git a/apps/emqx_authz/src/emqx_authz_schema.erl b/apps/emqx_authz/src/emqx_authz_schema.erl
index 5527c26d6..e68ab3a50 100644
--- a/apps/emqx_authz/src/emqx_authz_schema.erl
+++ b/apps/emqx_authz/src/emqx_authz_schema.erl
@@ -223,7 +223,7 @@ http_common_fields() ->
         {url, fun url/1},
         {request_timeout,
             mk_duration("Request timeout", #{
-                required => false, default => "30s", desc => ?DESC(request_timeout)
+                required => false, default => <<"30s">>, desc => ?DESC(request_timeout)
             })},
         {body, ?HOCON(map(), #{required => false, desc => ?DESC(body)})}
     ] ++
diff --git a/apps/emqx_conf/src/emqx_conf_schema.erl b/apps/emqx_conf/src/emqx_conf_schema.erl
index 9793e00d0..4862be5fe 100644
--- a/apps/emqx_conf/src/emqx_conf_schema.erl
+++ b/apps/emqx_conf/src/emqx_conf_schema.erl
@@ -145,7 +145,7 @@ fields("cluster") ->
                 emqx_schema:duration(),
                 #{
                     mapping => "ekka.cluster_autoclean",
-                    default => "5m",
+                    default => <<"5m">>,
                     desc => ?DESC(cluster_autoclean),
                     'readOnly' => true
                 }
@@ -214,7 +214,7 @@ fields(cluster_mcast) ->
             sc(
                 string(),
                 #{
-                    default => "239.192.0.1",
+                    default => <<"239.192.0.1">>,
                     desc => ?DESC(cluster_mcast_addr),
                     'readOnly' => true
                 }
@@ -232,7 +232,7 @@ fields(cluster_mcast) ->
             sc(
                 string(),
                 #{
-                    default => "0.0.0.0",
+                    default => <<"0.0.0.0">>,
                     desc => ?DESC(cluster_mcast_iface),
                     'readOnly' => true
                 }
@@ -259,7 +259,7 @@ fields(cluster_mcast) ->
             sc(
                 emqx_schema:bytesize(),
                 #{
-                    default => "16KB",
+                    default => <<"16KB">>,
                     desc => ?DESC(cluster_mcast_sndbuf),
                     'readOnly' => true
                 }
@@ -268,7 +268,7 @@ fields(cluster_mcast) ->
             sc(
                 emqx_schema:bytesize(),
                 #{
-                    default => "16KB",
+                    default => <<"16KB">>,
                     desc => ?DESC(cluster_mcast_recbuf),
                     'readOnly' => true
                 }
@@ -277,7 +277,7 @@ fields(cluster_mcast) ->
             sc(
                 emqx_schema:bytesize(),
                 #{
-                    default => "32KB",
+                    default => <<"32KB">>,
                     desc => ?DESC(cluster_mcast_buffer),
                     'readOnly' => true
                 }
@@ -289,7 +289,7 @@ fields(cluster_dns) ->
             sc(
                 string(),
                 #{
-                    default => "localhost",
+                    default => <<"localhost">>,
                     desc => ?DESC(cluster_dns_name),
                     'readOnly' => true
                 }
@@ -318,7 +318,7 @@ fields(cluster_etcd) ->
             sc(
                 string(),
                 #{
-                    default => "emqxcl",
+                    default => <<"emqxcl">>,
                     desc => ?DESC(cluster_etcd_prefix),
                     'readOnly' => true
                 }
@@ -327,7 +327,7 @@ fields(cluster_etcd) ->
             sc(
                 emqx_schema:duration(),
                 #{
-                    default => "1m",
+                    default => <<"1m">>,
                     'readOnly' => true,
                     desc => ?DESC(cluster_etcd_node_ttl)
                 }
@@ -347,7 +347,7 @@ fields(cluster_k8s) ->
             sc(
                 string(),
                 #{
-                    default => "http://10.110.111.204:8080",
+                    default => <<"http://10.110.111.204:8080">>,
                     desc => ?DESC(cluster_k8s_apiserver),
                     'readOnly' => true
                 }
@@ -356,7 +356,7 @@ fields(cluster_k8s) ->
             sc(
                 string(),
                 #{
-                    default => "emqx",
+                    default => <<"emqx">>,
                     desc => ?DESC(cluster_k8s_service_name),
                     'readOnly' => true
                 }
@@ -374,7 +374,7 @@ fields(cluster_k8s) ->
             sc(
                 string(),
                 #{
-                    default => "default",
+                    default => <<"default">>,
                     desc => ?DESC(cluster_k8s_namespace),
                     'readOnly' => true
                 }
@@ -383,7 +383,7 @@ fields(cluster_k8s) ->
             sc(
                 string(),
                 #{
-                    default => "pod.local",
+                    default => <<"pod.local">>,
                     'readOnly' => true,
                     desc => ?DESC(cluster_k8s_suffix)
                 }
@@ -395,7 +395,7 @@ fields("node") ->
             sc(
                 string(),
                 #{
-                    default => "emqx@127.0.0.1",
+                    default => <<"emqx@127.0.0.1">>,
                     'readOnly' => true,
                     desc => ?DESC(node_name)
                 }
@@ -477,7 +477,7 @@ fields("node") ->
                 hoconsc:union([disabled, emqx_schema:duration()]),
                 #{
                     mapping => "emqx_machine.global_gc_interval",
-                    default => "15m",
+                    default => <<"15m">>,
                     desc => ?DESC(node_global_gc_interval),
                     'readOnly' => true
                 }
@@ -497,7 +497,7 @@ fields("node") ->
                 emqx_schema:duration_s(),
                 #{
                     mapping => "vm_args.-env ERL_CRASH_DUMP_SECONDS",
-                    default => "30s",
+                    default => <<"30s">>,
                     desc => ?DESC(node_crash_dump_seconds),
                     'readOnly' => true
                 }
@@ -507,7 +507,7 @@ fields("node") ->
                 emqx_schema:bytesize(),
                 #{
                     mapping => "vm_args.-env ERL_CRASH_DUMP_BYTES",
-                    default => "100MB",
+                    default => <<"100MB">>,
                     desc => ?DESC(node_crash_dump_bytes),
                     'readOnly' => true
                 }
@@ -517,7 +517,7 @@ fields("node") ->
                 emqx_schema:duration_s(),
                 #{
                     mapping => "vm_args.-kernel net_ticktime",
-                    default => "2m",
+                    default => <<"2m">>,
                     'readOnly' => true,
                     desc => ?DESC(node_dist_net_ticktime)
                 }
@@ -624,7 +624,7 @@ fields("cluster_call") ->
                 emqx_schema:duration(),
                 #{
                     desc => ?DESC(cluster_call_retry_interval),
-                    default => "1m"
+                    default => <<"1m">>
                 }
             )},
         {"max_history",
@@ -640,7 +640,7 @@ fields("cluster_call") ->
                 emqx_schema:duration(),
                 #{
                     desc => ?DESC(cluster_call_cleanup_interval),
-                    default => "5m"
+                    default => <<"5m">>
                 }
             )}
     ];
@@ -712,7 +712,7 @@ fields("rpc") ->
                 emqx_schema:duration(),
                 #{
                     mapping => "gen_rpc.connect_timeout",
-                    default => "5s",
+                    default => <<"5s">>,
                     desc => ?DESC(rpc_connect_timeout)
                 }
             )},
@@ -745,7 +745,7 @@ fields("rpc") ->
                 emqx_schema:duration(),
                 #{
                     mapping => "gen_rpc.send_timeout",
-                    default => "5s",
+                    default => <<"5s">>,
                     desc => ?DESC(rpc_send_timeout)
                 }
             )},
@@ -754,7 +754,7 @@ fields("rpc") ->
                 emqx_schema:duration(),
                 #{
                     mapping => "gen_rpc.authentication_timeout",
-                    default => "5s",
+                    default => <<"5s">>,
                     desc => ?DESC(rpc_authentication_timeout)
                 }
             )},
@@ -763,7 +763,7 @@ fields("rpc") ->
                 emqx_schema:duration(),
                 #{
                     mapping => "gen_rpc.call_receive_timeout",
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC(rpc_call_receive_timeout)
                 }
             )},
@@ -772,7 +772,7 @@ fields("rpc") ->
                 emqx_schema:duration_s(),
                 #{
                     mapping => "gen_rpc.socket_keepalive_idle",
-                    default => "15m",
+                    default => <<"15m">>,
                     desc => ?DESC(rpc_socket_keepalive_idle)
                 }
             )},
@@ -781,7 +781,7 @@ fields("rpc") ->
                 emqx_schema:duration_s(),
                 #{
                     mapping => "gen_rpc.socket_keepalive_interval",
-                    default => "75s",
+                    default => <<"75s">>,
                     desc => ?DESC(rpc_socket_keepalive_interval)
                 }
             )},
@@ -799,7 +799,7 @@ fields("rpc") ->
                 emqx_schema:bytesize(),
                 #{
                     mapping => "gen_rpc.socket_sndbuf",
-                    default => "1MB",
+                    default => <<"1MB">>,
                     desc => ?DESC(rpc_socket_sndbuf)
                 }
             )},
@@ -808,7 +808,7 @@ fields("rpc") ->
                 emqx_schema:bytesize(),
                 #{
                     mapping => "gen_rpc.socket_recbuf",
-                    default => "1MB",
+                    default => <<"1MB">>,
                     desc => ?DESC(rpc_socket_recbuf)
                 }
             )},
@@ -817,7 +817,7 @@ fields("rpc") ->
                 emqx_schema:bytesize(),
                 #{
                     mapping => "gen_rpc.socket_buffer",
-                    default => "1MB",
+                    default => <<"1MB">>,
                     desc => ?DESC(rpc_socket_buffer)
                 }
             )},
@@ -861,7 +861,7 @@ fields("log_file_handler") ->
             sc(
                 hoconsc:union([infinity, emqx_schema:bytesize()]),
                 #{
-                    default => "50MB",
+                    default => <<"50MB">>,
                     desc => ?DESC("log_file_handler_max_size")
                 }
             )}
@@ -899,7 +899,7 @@ fields("log_overload_kill") ->
             sc(
                 emqx_schema:bytesize(),
                 #{
-                    default => "30MB",
+                    default => <<"30MB">>,
                     desc => ?DESC("log_overload_kill_mem_size")
                 }
             )},
@@ -915,7 +915,7 @@ fields("log_overload_kill") ->
             sc(
                 hoconsc:union([emqx_schema:duration_ms(), infinity]),
                 #{
-                    default => "5s",
+                    default => <<"5s">>,
                     desc => ?DESC("log_overload_kill_restart_after")
                 }
             )}
@@ -942,7 +942,7 @@ fields("log_burst_limit") ->
             sc(
                 emqx_schema:duration(),
                 #{
-                    default => "1s",
+                    default => <<"1s">>,
                     desc => ?DESC("log_burst_limit_window_time")
                 }
             )}
@@ -1092,7 +1092,7 @@ log_handler_common_confs(Enable) ->
             sc(
                 string(),
                 #{
-                    default => "system",
+                    default => <<"system">>,
                     desc => ?DESC("common_handler_time_offset"),
                     validator => fun validate_time_offset/1
                 }
@@ -1169,9 +1169,9 @@ crash_dump_file_default() ->
     case os:getenv("RUNNER_LOG_DIR") of
         false ->
             %% testing, or running emqx app as deps
-            "log/erl_crash.dump";
+            <<"log/erl_crash.dump">>;
         Dir ->
-            [filename:join([Dir, "erl_crash.dump"])]
+            unicode:characters_to_binary(filename:join([Dir, "erl_crash.dump"]), utf8)
     end.
 
 %% utils
diff --git a/apps/emqx_connector/src/emqx_connector_http.erl b/apps/emqx_connector/src/emqx_connector_http.erl
index 7c4a1fcf8..7d91e18b9 100644
--- a/apps/emqx_connector/src/emqx_connector_http.erl
+++ b/apps/emqx_connector/src/emqx_connector_http.erl
@@ -87,7 +87,7 @@ fields(config) ->
             sc(
                 emqx_schema:duration_ms(),
                 #{
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC("connect_timeout")
                 }
             )},
diff --git a/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl b/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl
index 073b75ae8..e08804685 100644
--- a/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl
+++ b/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl
@@ -115,12 +115,12 @@ fields("server_configs") ->
                     desc => ?DESC("clean_start")
                 }
             )},
-        {keepalive, mk_duration("MQTT Keepalive.", #{default => "300s"})},
+        {keepalive, mk_duration("MQTT Keepalive.", #{default => <<"300s">>})},
         {retry_interval,
             mk_duration(
                 "Message retry interval. Delay for the MQTT bridge to retry sending the QoS1/QoS2 "
                 "messages in case of ACK not received.",
-                #{default => "15s"}
+                #{default => <<"15s">>}
             )},
         {max_inflight,
             mk(
diff --git a/apps/emqx_dashboard/src/emqx_dashboard_schema.erl b/apps/emqx_dashboard/src/emqx_dashboard_schema.erl
index ceb2415f8..7df661fb2 100644
--- a/apps/emqx_dashboard/src/emqx_dashboard_schema.erl
+++ b/apps/emqx_dashboard/src/emqx_dashboard_schema.erl
@@ -40,7 +40,7 @@ fields("dashboard") ->
             ?HOCON(
                 emqx_schema:duration_s(),
                 #{
-                    default => "10s",
+                    default => <<"10s">>,
                     desc => ?DESC(sample_interval),
                     validator => fun validate_sample_interval/1
                 }
@@ -49,7 +49,7 @@ fields("dashboard") ->
             ?HOCON(
                 emqx_schema:duration(),
                 #{
-                    default => "60m",
+                    default => <<"60m">>,
                     desc => ?DESC(token_expired_time)
                 }
             )},
@@ -141,7 +141,7 @@ common_listener_fields() ->
             ?HOCON(
                 emqx_schema:duration(),
                 #{
-                    default => "10s",
+                    default => <<"10s">>,
                     desc => ?DESC(send_timeout)
                 }
             )},
@@ -206,14 +206,14 @@ desc(_) ->
     undefined.
 
 default_username(type) -> binary();
-default_username(default) -> "admin";
+default_username(default) -> <<"admin">>;
 default_username(required) -> true;
 default_username(desc) -> ?DESC(default_username);
 default_username('readOnly') -> true;
 default_username(_) -> undefined.
 
 default_password(type) -> binary();
-default_password(default) -> "public";
+default_password(default) -> <<"public">>;
 default_password(required) -> true;
 default_password('readOnly') -> true;
 default_password(sensitive) -> true;
diff --git a/apps/emqx_dashboard/test/emqx_swagger_remote_schema.erl b/apps/emqx_dashboard/test/emqx_swagger_remote_schema.erl
index a797d3b43..c2266ad5b 100644
--- a/apps/emqx_dashboard/test/emqx_swagger_remote_schema.erl
+++ b/apps/emqx_dashboard/test/emqx_swagger_remote_schema.erl
@@ -32,8 +32,8 @@ fields("root") ->
             )},
         {default_username, fun default_username/1},
         {default_password, fun default_password/1},
-        {sample_interval, mk(emqx_schema:duration_s(), #{default => "10s"})},
-        {token_expired_time, mk(emqx_schema:duration(), #{default => "30m"})}
+        {sample_interval, mk(emqx_schema:duration_s(), #{default => <<"10s">>})},
+        {token_expired_time, mk(emqx_schema:duration(), #{default => <<"30m">>})}
     ];
 fields("ref1") ->
     [
@@ -52,7 +52,7 @@ fields("ref3") ->
     ].
 
 default_username(type) -> string();
-default_username(default) -> "admin";
+default_username(default) -> <<"admin">>;
 default_username(required) -> true;
 default_username(_) -> undefined.
 
diff --git a/apps/emqx_dashboard/test/emqx_swagger_requestBody_SUITE.erl b/apps/emqx_dashboard/test/emqx_swagger_requestBody_SUITE.erl
index d17725e80..979d01c77 100644
--- a/apps/emqx_dashboard/test/emqx_swagger_requestBody_SUITE.erl
+++ b/apps/emqx_dashboard/test/emqx_swagger_requestBody_SUITE.erl
@@ -790,7 +790,7 @@ to_schema(Body) ->
 
 fields(good_ref) ->
     [
-        {'webhook-host', mk(emqx_schema:ip_port(), #{default => "127.0.0.1:80"})},
+        {'webhook-host', mk(emqx_schema:ip_port(), #{default => <<"127.0.0.1:80">>})},
         {log_dir, mk(emqx_schema:file(), #{example => "var/log/emqx"})},
         {tag, mk(binary(), #{desc => <<"tag">>})}
     ];
diff --git a/apps/emqx_dashboard/test/emqx_swagger_response_SUITE.erl b/apps/emqx_dashboard/test/emqx_swagger_response_SUITE.erl
index 346f4ef71..c9cfba254 100644
--- a/apps/emqx_dashboard/test/emqx_swagger_response_SUITE.erl
+++ b/apps/emqx_dashboard/test/emqx_swagger_response_SUITE.erl
@@ -689,7 +689,7 @@ to_schema(Object) ->
 
 fields(good_ref) ->
     [
-        {'webhook-host', mk(emqx_schema:ip_port(), #{default => "127.0.0.1:80"})},
+        {'webhook-host', mk(emqx_schema:ip_port(), #{default => <<"127.0.0.1:80">>})},
         {log_dir, mk(emqx_schema:file(), #{example => "var/log/emqx"})},
         {tag, mk(binary(), #{desc => <<"tag">>})}
     ];
diff --git a/apps/emqx_exhook/src/emqx_exhook.app.src b/apps/emqx_exhook/src/emqx_exhook.app.src
index d81819c98..04e0a57db 100644
--- a/apps/emqx_exhook/src/emqx_exhook.app.src
+++ b/apps/emqx_exhook/src/emqx_exhook.app.src
@@ -1,7 +1,7 @@
 %% -*- mode: erlang -*-
 {application, emqx_exhook, [
     {description, "EMQX Extension for Hook"},
-    {vsn, "5.0.9"},
+    {vsn, "5.0.10"},
     {modules, []},
     {registered, []},
     {mod, {emqx_exhook_app, []}},
diff --git a/apps/emqx_exhook/src/emqx_exhook_api.erl b/apps/emqx_exhook/src/emqx_exhook_api.erl
index 4d7de2866..bcfc68269 100644
--- a/apps/emqx_exhook/src/emqx_exhook_api.erl
+++ b/apps/emqx_exhook/src/emqx_exhook_api.erl
@@ -229,9 +229,9 @@ server_conf_schema() ->
             name => "default",
             enable => true,
             url => <<"http://127.0.0.1:8081">>,
-            request_timeout => "5s",
+            request_timeout => <<"5s">>,
             failed_action => deny,
-            auto_reconnect => "60s",
+            auto_reconnect => <<"60s">>,
             pool_size => 8,
             ssl => SSL
         }
diff --git a/apps/emqx_exhook/src/emqx_exhook_schema.erl b/apps/emqx_exhook/src/emqx_exhook_schema.erl
index ce79dddac..07373288d 100644
--- a/apps/emqx_exhook/src/emqx_exhook_schema.erl
+++ b/apps/emqx_exhook/src/emqx_exhook_schema.erl
@@ -63,7 +63,7 @@ fields(server) ->
             })},
         {request_timeout,
             ?HOCON(emqx_schema:duration(), #{
-                default => "5s",
+                default => <<"5s">>,
                 desc => ?DESC(request_timeout)
             })},
         {failed_action, failed_action()},
@@ -74,7 +74,7 @@ fields(server) ->
             })},
         {auto_reconnect,
             ?HOCON(hoconsc:union([false, emqx_schema:duration()]), #{
-                default => "60s",
+                default => <<"60s">>,
                 desc => ?DESC(auto_reconnect)
             })},
         {pool_size,
diff --git a/apps/emqx_gateway/src/emqx_gateway_schema.erl b/apps/emqx_gateway/src/emqx_gateway_schema.erl
index 4ea845ea1..2034a40eb 100644
--- a/apps/emqx_gateway/src/emqx_gateway_schema.erl
+++ b/apps/emqx_gateway/src/emqx_gateway_schema.erl
@@ -267,7 +267,7 @@ fields(lwm2m) ->
             sc(
                 duration(),
                 #{
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC(lwm2m_lifetime_min)
                 }
             )},
@@ -275,7 +275,7 @@ fields(lwm2m) ->
             sc(
                 duration(),
                 #{
-                    default => "86400s",
+                    default => <<"86400s">>,
                     desc => ?DESC(lwm2m_lifetime_max)
                 }
             )},
@@ -283,7 +283,7 @@ fields(lwm2m) ->
             sc(
                 duration_s(),
                 #{
-                    default => "22s",
+                    default => <<"22s">>,
                     desc => ?DESC(lwm2m_qmode_time_window)
                 }
             )},
@@ -624,7 +624,7 @@ mountpoint(Default) ->
     sc(
         binary(),
         #{
-            default => Default,
+            default => iolist_to_binary(Default),
             desc => ?DESC(gateway_common_mountpoint)
         }
     ).
@@ -707,7 +707,7 @@ proxy_protocol_opts() ->
             sc(
                 duration(),
                 #{
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC(tcp_listener_proxy_protocol_timeout)
                 }
             )}
diff --git a/apps/emqx_plugins/src/emqx_plugins.app.src b/apps/emqx_plugins/src/emqx_plugins.app.src
index de56099ba..ed893c80d 100644
--- a/apps/emqx_plugins/src/emqx_plugins.app.src
+++ b/apps/emqx_plugins/src/emqx_plugins.app.src
@@ -1,7 +1,7 @@
 %% -*- mode: erlang -*-
 {application, emqx_plugins, [
     {description, "EMQX Plugin Management"},
-    {vsn, "0.1.1"},
+    {vsn, "0.1.2"},
     {modules, []},
     {mod, {emqx_plugins_app, []}},
     {applications, [kernel, stdlib, emqx]},
diff --git a/apps/emqx_plugins/src/emqx_plugins_schema.erl b/apps/emqx_plugins/src/emqx_plugins_schema.erl
index 8b3cca8fd..9d9d045de 100644
--- a/apps/emqx_plugins/src/emqx_plugins_schema.erl
+++ b/apps/emqx_plugins/src/emqx_plugins_schema.erl
@@ -78,11 +78,11 @@ states(_) -> undefined.
 install_dir(type) -> string();
 install_dir(required) -> false;
 %% runner's root dir
-install_dir(default) -> "plugins";
+install_dir(default) -> <<"plugins">>;
 install_dir(T) when T =/= desc -> undefined;
 install_dir(desc) -> ?DESC(install_dir).
 
 check_interval(type) -> emqx_schema:duration();
-check_interval(default) -> "5s";
+check_interval(default) -> <<"5s">>;
 check_interval(T) when T =/= desc -> undefined;
 check_interval(desc) -> ?DESC(check_interval).
diff --git a/apps/emqx_prometheus/src/emqx_prometheus_schema.erl b/apps/emqx_prometheus/src/emqx_prometheus_schema.erl
index fcda5dea0..6ced0bf42 100644
--- a/apps/emqx_prometheus/src/emqx_prometheus_schema.erl
+++ b/apps/emqx_prometheus/src/emqx_prometheus_schema.erl
@@ -40,7 +40,7 @@ fields("prometheus") ->
             ?HOCON(
                 string(),
                 #{
-                    default => "http://127.0.0.1:9091",
+                    default => <<"http://127.0.0.1:9091">>,
                     required => true,
                     validator => fun ?MODULE:validate_push_gateway_server/1,
                     desc => ?DESC(push_gateway_server)
@@ -50,7 +50,7 @@ fields("prometheus") ->
             ?HOCON(
                 emqx_schema:duration_ms(),
                 #{
-                    default => "15s",
+                    default => <<"15s">>,
                     required => true,
                     desc => ?DESC(interval)
                 }
diff --git a/apps/emqx_retainer/src/emqx_retainer_schema.erl b/apps/emqx_retainer/src/emqx_retainer_schema.erl
index 472ecc284..dbe1ad9d5 100644
--- a/apps/emqx_retainer/src/emqx_retainer_schema.erl
+++ b/apps/emqx_retainer/src/emqx_retainer_schema.erl
@@ -41,13 +41,13 @@ fields("retainer") ->
             sc(
                 emqx_schema:duration_ms(),
                 msg_expiry_interval,
-                "0s"
+                <<"0s">>
             )},
         {msg_clear_interval,
             sc(
                 emqx_schema:duration_ms(),
                 msg_clear_interval,
-                "0s"
+                <<"0s">>
             )},
         {flow_control,
             sc(
@@ -59,7 +59,7 @@ fields("retainer") ->
             sc(
                 emqx_schema:bytesize(),
                 max_payload_size,
-                "1MB"
+                <<"1MB">>
             )},
         {stop_publish_clear_msg,
             sc(
diff --git a/apps/emqx_rule_engine/src/emqx_rule_engine_schema.erl b/apps/emqx_rule_engine/src/emqx_rule_engine_schema.erl
index d6913cbc6..2281eea53 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_engine_schema.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_engine_schema.erl
@@ -51,7 +51,7 @@ fields("rule_engine") ->
             ?HOCON(
                 emqx_schema:duration_ms(),
                 #{
-                    default => "10s",
+                    default => <<"10s">>,
                     desc => ?DESC("rule_engine_jq_function_default_timeout")
                 }
             )},
diff --git a/apps/emqx_slow_subs/src/emqx_slow_subs.app.src b/apps/emqx_slow_subs/src/emqx_slow_subs.app.src
index 866655b61..170a4bb02 100644
--- a/apps/emqx_slow_subs/src/emqx_slow_subs.app.src
+++ b/apps/emqx_slow_subs/src/emqx_slow_subs.app.src
@@ -1,7 +1,7 @@
 {application, emqx_slow_subs, [
     {description, "EMQX Slow Subscribers Statistics"},
     % strict semver, bump manually!
-    {vsn, "1.0.2"},
+    {vsn, "1.0.3"},
     {modules, []},
     {registered, [emqx_slow_subs_sup]},
     {applications, [kernel, stdlib, emqx]},
diff --git a/apps/emqx_slow_subs/src/emqx_slow_subs_schema.erl b/apps/emqx_slow_subs/src/emqx_slow_subs_schema.erl
index 8ae015ae4..9e9e6488a 100644
--- a/apps/emqx_slow_subs/src/emqx_slow_subs_schema.erl
+++ b/apps/emqx_slow_subs/src/emqx_slow_subs_schema.erl
@@ -30,13 +30,13 @@ fields("slow_subs") ->
         {threshold,
             sc(
                 emqx_schema:duration_ms(),
-                "500ms",
+                <<"500ms">>,
                 threshold
             )},
         {expire_interval,
             sc(
                 emqx_schema:duration_ms(),
-                "300s",
+                <<"300s">>,
                 expire_interval
             )},
         {top_k_num,
diff --git a/apps/emqx_statsd/src/emqx_statsd_api.erl b/apps/emqx_statsd/src/emqx_statsd_api.erl
index b1b3601aa..e65c93432 100644
--- a/apps/emqx_statsd/src/emqx_statsd_api.erl
+++ b/apps/emqx_statsd/src/emqx_statsd_api.erl
@@ -77,9 +77,9 @@ statsd_config_schema() ->
 statsd_example() ->
     #{
         enable => true,
-        flush_time_interval => "30s",
-        sample_time_interval => "30s",
-        server => "127.0.0.1:8125",
+        flush_time_interval => <<"30s">>,
+        sample_time_interval => <<"30s">>,
+        server => <<"127.0.0.1:8125">>,
         tags => #{}
     }.
 
diff --git a/apps/emqx_statsd/src/emqx_statsd_schema.erl b/apps/emqx_statsd/src/emqx_statsd_schema.erl
index 1e5aa6e5f..e44f94954 100644
--- a/apps/emqx_statsd/src/emqx_statsd_schema.erl
+++ b/apps/emqx_statsd/src/emqx_statsd_schema.erl
@@ -61,12 +61,12 @@ server() ->
     emqx_schema:servers_sc(Meta, ?SERVER_PARSE_OPTS).
 
 sample_interval(type) -> emqx_schema:duration_ms();
-sample_interval(default) -> "30s";
+sample_interval(default) -> <<"30s">>;
 sample_interval(desc) -> ?DESC(?FUNCTION_NAME);
 sample_interval(_) -> undefined.
 
 flush_interval(type) -> emqx_schema:duration_ms();
-flush_interval(default) -> "30s";
+flush_interval(default) -> <<"30s">>;
 flush_interval(desc) -> ?DESC(?FUNCTION_NAME);
 flush_interval(_) -> undefined.
 
diff --git a/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_gcp_pubsub.erl b/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_gcp_pubsub.erl
index 1bee9e789..e00483839 100644
--- a/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_gcp_pubsub.erl
+++ b/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_gcp_pubsub.erl
@@ -50,7 +50,7 @@ fields(bridge_config) ->
             sc(
                 emqx_schema:duration_ms(),
                 #{
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC("connect_timeout")
                 }
             )},
@@ -84,7 +84,7 @@ fields(bridge_config) ->
                 emqx_schema:duration_ms(),
                 #{
                     required => false,
-                    default => "15s",
+                    default => <<"15s">>,
                     desc => ?DESC("request_timeout")
                 }
             )},
diff --git a/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_kafka.erl b/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_kafka.erl
index e694f6c15..3983b235c 100644
--- a/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_kafka.erl
+++ b/lib-ee/emqx_ee_bridge/src/emqx_ee_bridge_kafka.erl
@@ -84,20 +84,20 @@ fields("config") ->
             )},
         {connect_timeout,
             mk(emqx_schema:duration_ms(), #{
-                default => "5s",
+                default => <<"5s">>,
                 desc => ?DESC(connect_timeout)
             })},
         {min_metadata_refresh_interval,
             mk(
                 emqx_schema:duration_ms(),
                 #{
-                    default => "3s",
+                    default => <<"3s">>,
                     desc => ?DESC(min_metadata_refresh_interval)
                 }
             )},
         {metadata_request_timeout,
             mk(emqx_schema:duration_ms(), #{
-                default => "5s",
+                default => <<"5s">>,
                 desc => ?DESC(metadata_request_timeout)
             })},
         {authentication,
@@ -141,12 +141,12 @@ fields(socket_opts) ->
         {sndbuf,
             mk(
                 emqx_schema:bytesize(),
-                #{default => "1024KB", desc => ?DESC(socket_send_buffer)}
+                #{default => <<"1024KB">>, desc => ?DESC(socket_send_buffer)}
             )},
         {recbuf,
             mk(
                 emqx_schema:bytesize(),
-                #{default => "1024KB", desc => ?DESC(socket_receive_buffer)}
+                #{default => <<"1024KB">>, desc => ?DESC(socket_receive_buffer)}
             )},
         {nodelay,
             mk(
@@ -170,7 +170,7 @@ fields(producer_kafka_opts) ->
         {topic, mk(string(), #{required => true, desc => ?DESC(kafka_topic)})},
         {message, mk(ref(kafka_message), #{required => false, desc => ?DESC(kafka_message)})},
         {max_batch_bytes,
-            mk(emqx_schema:bytesize(), #{default => "896KB", desc => ?DESC(max_batch_bytes)})},
+            mk(emqx_schema:bytesize(), #{default => <<"896KB">>, desc => ?DESC(max_batch_bytes)})},
         {compression,
             mk(enum([no_compression, snappy, gzip]), #{
                 default => no_compression, desc => ?DESC(compression)
@@ -192,7 +192,7 @@ fields(producer_kafka_opts) ->
             mk(
                 emqx_schema:duration_s(),
                 #{
-                    default => "60s",
+                    default => <<"60s">>,
                     desc => ?DESC(partition_count_refresh_interval)
                 }
             )},
@@ -212,11 +212,11 @@ fields(producer_kafka_opts) ->
     ];
 fields(kafka_message) ->
     [
-        {key, mk(string(), #{default => "${.clientid}", desc => ?DESC(kafka_message_key)})},
-        {value, mk(string(), #{default => "${.}", desc => ?DESC(kafka_message_value)})},
+        {key, mk(string(), #{default => <<"${.clientid}">>, desc => ?DESC(kafka_message_key)})},
+        {value, mk(string(), #{default => <<"${.}">>, desc => ?DESC(kafka_message_value)})},
         {timestamp,
             mk(string(), #{
-                default => "${.timestamp}", desc => ?DESC(kafka_message_timestamp)
+                default => <<"${.timestamp}">>, desc => ?DESC(kafka_message_timestamp)
             })}
     ];
 fields(producer_buffer) ->
@@ -229,12 +229,12 @@ fields(producer_buffer) ->
         {per_partition_limit,
             mk(
                 emqx_schema:bytesize(),
-                #{default => "2GB", desc => ?DESC(buffer_per_partition_limit)}
+                #{default => <<"2GB">>, desc => ?DESC(buffer_per_partition_limit)}
             )},
         {segment_bytes,
             mk(
                 emqx_schema:bytesize(),
-                #{default => "100MB", desc => ?DESC(buffer_segment_bytes)}
+                #{default => <<"100MB">>, desc => ?DESC(buffer_segment_bytes)}
             )},
         {memory_overload_protection,
             mk(boolean(), #{
diff --git a/lib-ee/emqx_license/src/emqx_license_schema.erl b/lib-ee/emqx_license/src/emqx_license_schema.erl
index 9d16f697c..7383af92c 100644
--- a/lib-ee/emqx_license/src/emqx_license_schema.erl
+++ b/lib-ee/emqx_license/src/emqx_license_schema.erl
@@ -46,12 +46,12 @@ fields(key_license) ->
         }},
         {connection_low_watermark, #{
             type => emqx_schema:percent(),
-            default => "75%",
+            default => <<"75%">>,
             desc => ?DESC(connection_low_watermark_field)
         }},
         {connection_high_watermark, #{
             type => emqx_schema:percent(),
-            default => "80%",
+            default => <<"80%">>,
             desc => ?DESC(connection_high_watermark_field)
         }}
     ].