diff --git a/lib-opensource/emqx_management/src/emqx_mgmt.erl b/lib-opensource/emqx_management/src/emqx_mgmt.erl
index aebb43f69..26b55b249 100644
--- a/lib-opensource/emqx_management/src/emqx_mgmt.erl
+++ b/lib-opensource/emqx_management/src/emqx_mgmt.erl
@@ -302,14 +302,20 @@ lookup_client({username, Username}, FormatFun) ->
     lists:append([lookup_client(Node, {username, Username}, FormatFun) || Node <- ekka_mnesia:running_nodes()]).
 
 lookup_client(Node, {clientid, ClientId}, {M,F}) when Node =:= node() ->
-    lists:map(fun(E) -> M:F(E) end, ets:lookup(emqx_channel, ClientId));
+    lists:append(lists:map(
+      fun(Key) ->
+        lists:map(fun M:F/1, ets:lookup(emqx_channel_info, Key))
+      end, ets:lookup(emqx_channel, ClientId)));
 
 lookup_client(Node, {clientid, ClientId}, FormatFun) ->
     rpc_call(Node, lookup_client, [Node, {clientid, ClientId}, FormatFun]);
 
 lookup_client(Node, {username, Username}, {M,F}) when Node =:= node() ->
-    MatchSpec = [{{'$1', #{clientinfo => #{username => '$2'}}, '_'}, [{'=:=','$2', Username}], ['$1']}],
-    lists:map(fun(E) -> M:F(E) end, ets:select(emqx_channel_info, MatchSpec));
+    MatchSpec = [{ {'_', #{clientinfo => #{username => '$1'}}, '_'}
+                 , [{'=:=','$1', Username}]
+                 , ['$_']
+                 }],
+    lists:map(fun M:F/1, ets:select(emqx_channel_info, MatchSpec));
 
 lookup_client(Node, {username, Username}, FormatFun) ->
     rpc_call(Node, lookup_client, [Node, {username, Username}, FormatFun]).
diff --git a/lib-opensource/emqx_management/src/emqx_mgmt_api_clients.erl b/lib-opensource/emqx_management/src/emqx_mgmt_api_clients.erl
index 18420cfb4..7a4e4b0b7 100644
--- a/lib-opensource/emqx_management/src/emqx_mgmt_api_clients.erl
+++ b/lib-opensource/emqx_management/src/emqx_mgmt_api_clients.erl
@@ -249,10 +249,6 @@ parse_ratelimit_str(S) ->
 %%--------------------------------------------------------------------
 %% Format
 
-format_channel_info(Key = {_ClientId, _Pid}) ->
-    [E] = ets:lookup(emqx_channel_info, Key),
-    format_channel_info(E);
-
 format_channel_info({_Key, Info, Stats0}) ->
     Stats = maps:from_list(Stats0),
     ClientInfo = maps:get(clientinfo, Info, #{}),