diff --git a/apps/emqx/src/emqx_schema.erl b/apps/emqx/src/emqx_schema.erl
index 85b411217..a0bdb5150 100644
--- a/apps/emqx/src/emqx_schema.erl
+++ b/apps/emqx/src/emqx_schema.erl
@@ -38,7 +38,6 @@
 -type ip_port() :: tuple().
 -type cipher() :: map().
 -type rfc3339_system_time() :: integer().
--type unicode_binary() :: binary().
 
 -typerefl_from_string({duration/0, emqx_schema, to_duration}).
 -typerefl_from_string({duration_s/0, emqx_schema, to_duration_s}).
@@ -52,7 +51,6 @@
 -typerefl_from_string({cipher/0, emqx_schema, to_erl_cipher_suite}).
 -typerefl_from_string({comma_separated_atoms/0, emqx_schema, to_comma_separated_atoms}).
 -typerefl_from_string({rfc3339_system_time/0, emqx_schema, rfc3339_to_system_time}).
--typerefl_from_string({unicode_binary/0, emqx_schema, to_unicode_binary}).
 
 -export([ validate_heap_size/1
         , parse_user_lookup_fun/1
@@ -66,8 +64,7 @@
          to_bar_separated_list/1, to_ip_port/1,
          to_erl_cipher_suite/1,
          to_comma_separated_atoms/1,
-         rfc3339_to_system_time/1,
-         to_unicode_binary/1]).
+         rfc3339_to_system_time/1]).
 
 -behaviour(hocon_schema).
 
@@ -76,8 +73,7 @@
                 comma_separated_list/0, bar_separated_list/0, ip_port/0,
                 cipher/0,
                 comma_separated_atoms/0,
-                rfc3339_system_time/0,
-                unicode_binary/0]).
+                rfc3339_system_time/0]).
 
 -export([namespace/0, roots/0, roots/1, fields/1]).
 -export([conf_get/2, conf_get/3, keys/2, filter/1]).
@@ -1390,9 +1386,6 @@ rfc3339_to_system_time(DateTime) ->
         {error, bad_rfc3339_timestamp}
     end.
 
-to_unicode_binary(Str) ->
-    {ok, unicode:characters_to_binary(Str)}.
-
 to_bar_separated_list(Str) ->
     {ok, string:tokens(Str, "| ")}.
 
diff --git a/apps/emqx_dashboard/src/emqx_dashboard_api.erl b/apps/emqx_dashboard/src/emqx_dashboard_api.erl
index 45a3b7c56..ae2eb4e42 100644
--- a/apps/emqx_dashboard/src/emqx_dashboard_api.erl
+++ b/apps/emqx_dashboard/src/emqx_dashboard_api.erl
@@ -123,7 +123,7 @@ schema("/users/:username") ->
                 #{in => path, example => <<"admin">>})}],
             'requestBody' => [
                 { description
-                , mk(emqx_schema:unicode_binary(),
+                , mk(binary(),
                     #{desc => <<"User description">>, example => <<"administrator">>})}
             ],
             responses => #{
@@ -176,7 +176,7 @@ schema("/users/:username/change_pwd") ->
 fields(user) ->
     [
         {description,
-            mk(emqx_schema:unicode_binary(),
+            mk(binary(),
                 #{desc => <<"User description">>, example => "administrator"})},
         {username,
             mk(binary(),
diff --git a/apps/emqx_management/src/emqx_mgmt_api_app.erl b/apps/emqx_management/src/emqx_mgmt_api_app.erl
index b77f1a214..53ad01485 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_app.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_app.erl
@@ -100,7 +100,7 @@ fields(app) ->
             #{desc => "ApiKey create datetime",
                 example => <<"2021-12-01T00:00:00.000Z">>
             })},
-        {desc, hoconsc:mk(emqx_schema:unicode_binary(),
+        {desc, hoconsc:mk(binary(),
             #{example => <<"Note">>, nullable => true})},
         {enable, hoconsc:mk(boolean(), #{desc => "Enable/Disable", nullable => true})}
     ];
diff --git a/apps/emqx_management/src/emqx_mgmt_api_banned.erl b/apps/emqx_management/src/emqx_mgmt_api_banned.erl
index 911b298a1..c6ff56ad0 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_banned.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_banned.erl
@@ -101,15 +101,15 @@ fields(ban) ->
             desc => <<"Banned type clientid, username, peerhost">>,
             nullable => false,
             example => username})},
-        {who, hoconsc:mk(emqx_schema:unicode_binary(), #{
+        {who, hoconsc:mk(binary(), #{
             desc => <<"Client info as banned type">>,
             nullable => false,
             example => <<"Badass坏"/utf8>>})},
-        {by, hoconsc:mk(emqx_schema:unicode_binary(), #{
+        {by, hoconsc:mk(binary(), #{
             desc => <<"Commander">>,
             nullable => true,
             example => <<"mgmt_api">>})},
-        {reason, hoconsc:mk(emqx_schema:unicode_binary(), #{
+        {reason, hoconsc:mk(binary(), #{
             desc => <<"Banned reason">>,
             nullable => true,
             example => <<"Too many requests">>})},