diff --git a/apps/emqx_authz/src/emqx_authz.erl b/apps/emqx_authz/src/emqx_authz.erl
index da776f291..9ba67ddd1 100644
--- a/apps/emqx_authz/src/emqx_authz.erl
+++ b/apps/emqx_authz/src/emqx_authz.erl
@@ -151,8 +151,9 @@ pre_config_update({{replace_once, Type}, Source}, Conf) when is_map(Source), is_
         Error -> Error
     end;
 pre_config_update({{delete_once, Type}, _Source}, Conf) when is_list(Conf) ->
-    {_, Source} = find_source_by_type(Type),
-    NConf = lists:delete(Source, Conf),
+    {Index, _} = find_source_by_type(Type),
+    {List1, List2} = lists:split(Index, Conf),
+    NConf = lists:droplast(List1)  ++ List2,
     case check_dup_types(NConf) of
         ok -> {ok, NConf};
         Error -> Error
diff --git a/apps/emqx_authz/src/emqx_authz_api_sources.erl b/apps/emqx_authz/src/emqx_authz_api_sources.erl
index acef52f44..54ac28409 100644
--- a/apps/emqx_authz/src/emqx_authz_api_sources.erl
+++ b/apps/emqx_authz/src/emqx_authz_api_sources.erl
@@ -336,11 +336,8 @@ sources(get, _) ->
                                   lists:append(AccIn, [Source#{annotations => #{status => healthy}}])
                         end, [], emqx_authz:lookup()),
     {200, #{sources => Sources}};
-sources(post, #{body := #{<<"type">> := <<"file">>, <<"rules">> := Rules}}) when is_list(Rules) ->
-    {ok, Filename} = write_file(filename:join([emqx:get_config([node, data_dir]), "acl.conf"]),
-                                erlang:list_to_bitstring([<<Rule/binary, "\n">> || Rule <- Rules])
-                               ),
-
+sources(post, #{body := #{<<"type">> := <<"file">>, <<"rules">> := Rules}}) ->
+    {ok, Filename} = write_file(filename:join([emqx:get_config([node, data_dir]), "acl.conf"]), Rules),
     update_config(head, [#{type => file, enable => true, path => Filename}]);
 sources(post, #{body := Body}) when is_map(Body) ->
     update_config(head, [write_cert(Body)]);
diff --git a/apps/emqx_authz/test/emqx_authz_api_sources_SUITE.erl b/apps/emqx_authz/test/emqx_authz_api_sources_SUITE.erl
index b4b7b87c9..3862e06d0 100644
--- a/apps/emqx_authz/test/emqx_authz_api_sources_SUITE.erl
+++ b/apps/emqx_authz/test/emqx_authz_api_sources_SUITE.erl
@@ -219,6 +219,7 @@ t_api(_) ->
                   end, Sources),
     {ok, 200, Result5} = request(get, uri(["authorization", "sources"]), []),
     ?assertEqual([], get_sources(Result5)),
+    ?assertEqual([], emqx:get_config([authorization, sources])),
     ok.
 
 t_move_source(_) ->