diff --git a/apps/emqx/src/emqx_sys.erl b/apps/emqx/src/emqx_sys.erl
index 0d3a78fef..3ba331b69 100644
--- a/apps/emqx/src/emqx_sys.erl
+++ b/apps/emqx/src/emqx_sys.erl
@@ -175,7 +175,7 @@ terminate(_Reason, #state{heartbeat = TRef1, ticker = TRef2}) ->
     lists:foreach(fun emqx_misc:cancel_timer/1, [TRef1, TRef2]).
 
 unload_event_hooks() ->
-    lists:foreach(fun(K, _) ->
+    maps:foreach(fun(K, _) ->
         {HookPoint, Fun} = hook_and_fun(K),
         emqx_hooks:del(HookPoint, {?MODULE, Fun})
     end, sys_event_message()).
diff --git a/apps/emqx/test/emqx_sys_SUITE.erl b/apps/emqx/test/emqx_sys_SUITE.erl
index 094778c0e..6af42ca85 100644
--- a/apps/emqx/test/emqx_sys_SUITE.erl
+++ b/apps/emqx/test/emqx_sys_SUITE.erl
@@ -32,21 +32,3 @@ end_per_suite(_Config) ->
     application:unload(emqx),
     ok = emqx_logger:set_log_level(error),
     ok.
-    
-% t_version(_) ->
-%     error('TODO').
-
-% t_sysdescr(_) ->
-%     error('TODO').
-
-% t_datetime(_) ->
-%     error('TODO').
-
-% t_sys_interval(_) ->
-%     error('TODO').
-
-% t_sys_heatbeat_interval(_) ->
-%     error('TODO').
-
-% t_info(_) ->
-%     error('TODO').
diff --git a/apps/emqx/test/props/prop_emqx_sys.erl b/apps/emqx/test/props/prop_emqx_sys.erl
index 780992951..12ca0842c 100644
--- a/apps/emqx/test/props/prop_emqx_sys.erl
+++ b/apps/emqx/test/props/prop_emqx_sys.erl
@@ -30,6 +30,7 @@
         , emqx_stats
         , emqx_broker
         , mria_mnesia
+        , emqx_hooks
         ]).
 
 -define(ALL(Vars, Types, Exprs),
@@ -59,8 +60,11 @@ prop_sys() ->
 
 do_setup() ->
     ok = emqx_logger:set_log_level(emergency),
-    emqx_config:put([broker, sys_msg_interval], 60000),
-    emqx_config:put([broker, sys_heartbeat_interval], 30000),
+    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],
+                    #{client_connected => true, client_disconnected => true,
+                      client_subscribed => true, client_unsubscribed => true}),
     [mock(Mod) || Mod <- ?mock_modules],
     ok.
 
@@ -83,7 +87,10 @@ do_mock(emqx_stats) ->
 do_mock(mria_mnesia) ->
     meck:expect(mria_mnesia, running_nodes, fun() -> [node()] end);
 do_mock(emqx_metrics) ->
-    meck:expect(emqx_metrics, all, fun() -> [{hello, 3}] end).
+    meck:expect(emqx_metrics, all, fun() -> [{hello, 3}] end);
+do_mock(emqx_hooks) ->
+    meck:expect(emqx_hooks, put, fun(_HookPoint, _MFA) -> ok end),
+    meck:expect(emqx_hooks, del, fun(_HookPoint, _MF) -> ok end).
 
 %%--------------------------------------------------------------------
 %% MODEL