diff --git a/apps/emqx/src/emqx_config.erl b/apps/emqx/src/emqx_config.erl
index 16d9f31a7..f5ff64d4d 100644
--- a/apps/emqx/src/emqx_config.erl
+++ b/apps/emqx/src/emqx_config.erl
@@ -446,7 +446,7 @@ fill_defaults(RawConf, Opts) ->
 
 -spec fill_defaults(module(), raw_config(), hocon_tconf:opts()) -> map().
 fill_defaults(SchemaMod, RawConf, Opts0) ->
-    Opts = maps:merge(#{required => false, only_fill_defaults => true}, Opts0),
+    Opts = maps:merge(#{required => false, make_serializable => true}, Opts0),
     hocon_tconf:check_plain(
         SchemaMod,
         RawConf,
diff --git a/apps/emqx_authn/src/emqx_authn_api.erl b/apps/emqx_authn/src/emqx_authn_api.erl
index 8f67ba210..8898f1d4c 100644
--- a/apps/emqx_authn/src/emqx_authn_api.erl
+++ b/apps/emqx_authn/src/emqx_authn_api.erl
@@ -1133,7 +1133,7 @@ find_config(AuthenticatorID, AuthenticatorsConfig) ->
 fill_defaults(Configs) when is_list(Configs) ->
     lists:map(fun fill_defaults/1, Configs);
 fill_defaults(Config) ->
-    emqx_authn:check_config(merge_default_headers(Config), #{only_fill_defaults => true}).
+    emqx_authn:check_config(merge_default_headers(Config), #{make_serialiable => true}).
 
 merge_default_headers(Config) ->
     case maps:find(<<"headers">>, Config) of
diff --git a/apps/emqx_authz/src/emqx_authz_api_sources.erl b/apps/emqx_authz/src/emqx_authz_api_sources.erl
index 3af2988db..3e67d4749 100644
--- a/apps/emqx_authz/src/emqx_authz_api_sources.erl
+++ b/apps/emqx_authz/src/emqx_authz_api_sources.erl
@@ -451,8 +451,7 @@ get_raw_sources() ->
     RawSources = emqx:get_raw_config([authorization, sources], []),
     Schema = #{roots => emqx_authz_schema:fields("authorization"), fields => #{}},
     Conf = #{<<"sources">> => RawSources},
-    Options = #{only_fill_defaults => true},
-    #{<<"sources">> := Sources} = hocon_tconf:check_plain(Schema, Conf, Options),
+    #{<<"sources">> := Sources} = hocon_tconf:make_serializable(Schema, Conf, #{}),
     merge_default_headers(Sources).
 
 merge_default_headers(Sources) ->
diff --git a/apps/emqx_exhook/src/emqx_exhook_api.erl b/apps/emqx_exhook/src/emqx_exhook_api.erl
index 6676c4503..c342ea66a 100644
--- a/apps/emqx_exhook/src/emqx_exhook_api.erl
+++ b/apps/emqx_exhook/src/emqx_exhook_api.erl
@@ -484,8 +484,7 @@ get_raw_config() ->
     RawConfig = emqx:get_raw_config([exhook, servers], []),
     Schema = #{roots => emqx_exhook_schema:fields(exhook), fields => #{}},
     Conf = #{<<"servers">> => RawConfig},
-    Options = #{only_fill_defaults => true},
-    #{<<"servers">> := Servers} = hocon_tconf:check_plain(Schema, Conf, Options),
+    #{<<"servers">> := Servers} = hocon_tconf:make_serializable(Schema, Conf, #{}),
     Servers.
 
 position_example() ->