diff --git a/src/emqttd_cli.erl b/src/emqttd_cli.erl
index 6f78d4745..c193aac91 100644
--- a/src/emqttd_cli.erl
+++ b/src/emqttd_cli.erl
@@ -43,6 +43,8 @@
          clients/1, sessions/1, plugins/1, listeners/1,
          vm/1, mnesia/1, trace/1]).
 
+-export([node_name/1]).
+
 -define(PROC_INFOKEYS, [status,
                         memory,
                         message_queue_len,
diff --git a/src/emqttd_ctl.erl b/src/emqttd_ctl.erl
index 86f7d8b3b..b02bab7ad 100644
--- a/src/emqttd_ctl.erl
+++ b/src/emqttd_ctl.erl
@@ -110,7 +110,13 @@ handle_call(_Request, _From, State) ->
     {reply, ok, State}.
 
 handle_cast({register_cmd, Cmd, MF, Opts}, State = #state{seq = Seq}) ->
-    ets:insert(?CMD_TAB, {{Seq, Cmd}, MF, Opts}),
+    case ets:match(?CMD_TAB, {{'$1', Cmd}, '_', '_'}) of
+        [] ->
+            ets:insert(?CMD_TAB, {{Seq, Cmd}, MF, Opts});
+        [[OriginSeq] | _] ->
+            lager:warning("CLI: ~s is overidden by ~p", [Cmd, MF]),
+            ets:insert(?CMD_TAB, {{OriginSeq, Cmd}, MF, Opts})
+    end,
     noreply(next_seq(State));
 
 handle_cast({unregister_cmd, Cmd}, State) ->