diff --git a/apps/emqx/etc/emqx.conf b/apps/emqx/etc/emqx.conf
index e47e8d04e..e6249a039 100644
--- a/apps/emqx/etc/emqx.conf
+++ b/apps/emqx/etc/emqx.conf
@@ -1083,7 +1083,7 @@ broker {
 ## System Topic
 ##==================================================================
 
-sys_topic {
+sys_topics {
   ## System interval of publishing $SYS messages.
   ##
   ## @doc broker.sys_msg_interval
diff --git a/apps/emqx/src/emqx_schema.erl b/apps/emqx/src/emqx_schema.erl
index 01b93cc06..94de42e31 100644
--- a/apps/emqx/src/emqx_schema.erl
+++ b/apps/emqx/src/emqx_schema.erl
@@ -144,8 +144,8 @@ roots(medium) ->
     [ {"broker",
        sc(ref("broker"),
          #{})}
-    , {"sys_topic",
-       sc(ref("sys_topic"),
+    , {"sys_topics",
+       sc(ref("sys_topics"),
           #{})}
     , {"rate_limit",
        sc(ref("rate_limit"),
@@ -902,7 +902,7 @@ fields("broker_perf") ->
            })}
     ];
 
-fields("sys_topic") ->
+fields("sys_topics") ->
     [ {"sys_msg_interval",
        sc(hoconsc:union([disabled, duration()]),
           #{ default => "1m"
diff --git a/apps/emqx/src/emqx_sys.erl b/apps/emqx/src/emqx_sys.erl
index 3ba331b69..9b10ba23b 100644
--- a/apps/emqx/src/emqx_sys.erl
+++ b/apps/emqx/src/emqx_sys.erl
@@ -107,13 +107,13 @@ datetime() ->
             "~4..0w-~2..0w-~2..0w ~2..0w:~2..0w:~2..0w", [Y, M, D, H, MM, S])).
 
 sys_interval() ->
-    emqx:get_config([sys_topic, sys_msg_interval]).
+    emqx:get_config([sys_topics, sys_msg_interval]).
 
 sys_heatbeat_interval() ->
-    emqx:get_config([sys_topic, sys_heartbeat_interval]).
+    emqx:get_config([sys_topics, sys_heartbeat_interval]).
 
 sys_event_message() ->
-    emqx:get_config([sys_topic, sys_event_messages]).
+    emqx:get_config([sys_topics, sys_event_messages]).
 
 %% @doc Get sys info
 -spec(info() -> list(tuple())).
@@ -138,12 +138,12 @@ tick(State) ->
     State#state{ticker = start_timer(sys_interval(), tick)}.
 
 load_event_hooks() ->
-    maps:foreach(
-      fun(_, false) -> ok;
-         (K, true) ->
+    lists:foreach(
+      fun({_, false}) -> ok;
+         ({K, true}) ->
             {HookPoint, Fun} = hook_and_fun(K),
             emqx_hooks:put(HookPoint, {?MODULE, Fun, []})
-      end, sys_event_message()).
+      end, maps:to_list(sys_event_message())).
 
 handle_call(Req, _From, State) ->
     ?SLOG(error, #{msg => "unexpected_call", call => Req}),
@@ -175,10 +175,10 @@ terminate(_Reason, #state{heartbeat = TRef1, ticker = TRef2}) ->
     lists:foreach(fun emqx_misc:cancel_timer/1, [TRef1, TRef2]).
 
 unload_event_hooks() ->
-    maps:foreach(fun(K, _) ->
+    lists:foreach(fun({K, _}) ->
         {HookPoint, Fun} = hook_and_fun(K),
         emqx_hooks:del(HookPoint, {?MODULE, Fun})
-    end, sys_event_message()).
+    end, maps:to_list(sys_event_message())).
 
 %%--------------------------------------------------------------------
 %% hook callbacks
diff --git a/apps/emqx/test/props/prop_emqx_sys.erl b/apps/emqx/test/props/prop_emqx_sys.erl
index 12ca0842c..c65383d81 100644
--- a/apps/emqx/test/props/prop_emqx_sys.erl
+++ b/apps/emqx/test/props/prop_emqx_sys.erl
@@ -60,9 +60,9 @@ prop_sys() ->
 
 do_setup() ->
     ok = emqx_logger:set_log_level(emergency),
-    emqx_config:put([sys_topic, sys_msg_interval], 60000),
-    emqx_config:put([sys_topic, sys_heartbeat_interval], 30000),
-    emqx_config:put([sys_topic, sys_event_messages],
+    emqx_config:put([sys_topics, sys_msg_interval], 60000),
+    emqx_config:put([sys_topics, sys_heartbeat_interval], 30000),
+    emqx_config:put([sys_topics, sys_event_messages],
                     #{client_connected => true, client_disconnected => true,
                       client_subscribed => true, client_unsubscribed => true}),
     [mock(Mod) || Mod <- ?mock_modules],