diff --git a/src/mtp_handler.erl b/src/mtp_handler.erl
index 32452a3..d58aeb3 100644
--- a/src/mtp_handler.erl
+++ b/src/mtp_handler.erl
@@ -135,14 +135,15 @@ handle_cast({proxy_ans, Down, Data}, #state{down = Down, srv_error_filter = off}
     {ok, S1} = up_send(Data, S),
     ok = mtp_down_conn:ack(Down, 1, iolist_size(Data)),
     maybe_check_health(bump_timer(S1));
-handle_cast({proxy_ans, Down, ?SRV_ERROR = Data}, #state{down = Down, srv_error_filter = Filter,
-                                                         addr = {Ip, _}} = S) when Filter =/= off ->
+handle_cast({proxy_ans, Down, ?SRV_ERROR = Data},
+            #state{down = Down, srv_error_filter = Filter, listener = Listener,
+                   addr = {Ip, _}} = S) when Filter =/= off ->
     %% telegram server -> proxy
     %% Server replied with server error; it might be another kind of replay attack;
     %% Don't send this packet to client so proxy won't be fingerprinted
     ok = mtp_down_conn:ack(Down, 1, iolist_size(Data)),
     ?log(warning, "~s: protocol_error srv_error_filtered", [inet:ntoa(Ip)]),
-    mtp_metric:count_inc([?APP, protocol_error, total], 1, #{labels => [srv_error_filtered]}),
+    mtp_metric:count_inc([?APP, protocol_error, total], 1, #{labels => [Listener, srv_error_filtered]}),
     {noreply,
      case Filter of
          first -> S#state{srv_error_filter = off};
@@ -182,7 +183,7 @@ handle_info({tcp, Sock, Data}, #state{sock = Sock, transport = Transport,
             %% Consider checking health here as well
             {noreply, bump_timer(S1)}
     catch error:{protocol_error, Type, Extra} ->
-            mtp_metric:count_inc([?APP, protocol_error, total], 1, #{labels => [Type]}),
+            mtp_metric:count_inc([?APP, protocol_error, total], 1, #{labels => [Listener, Type]}),
             ?log(warning, "~s: protocol_error ~p ~p", [inet:ntoa(Ip), Type, Extra]),
             {stop, normal, maybe_close_down(S)}
     end;
@@ -333,7 +334,7 @@ parse_upstream_data(<<Header:64/binary, Rest/binary>>,
                         stage = tunnel},
                 hibernate));
         {error, Reason} when is_atom(Reason) ->
-            mtp_metric:count_inc([?APP, protocol_error, total], 1, #{labels => [Reason]}),
+            mtp_metric:count_inc([?APP, protocol_error, total], 1, #{labels => [Listener, Reason]}),
             error({protocol_error, Reason, Header})
     end;
 parse_upstream_data(Bin, #state{stage = Stage, codec = Codec0} = S) when Stage =/= tunnel ->
diff --git a/src/mtp_metric.erl b/src/mtp_metric.erl
index c2a5717..5fec7cb 100644
--- a/src/mtp_metric.erl
+++ b/src/mtp_metric.erl
@@ -158,7 +158,7 @@ active_metrics() ->
 
      {count, [?APP, protocol_error, total],
       "Proxy protocol errors",
-      #{labels => [reason]}},
+      #{labels => [listener, reason]}},
      {count, [?APP, protocol_ok, total],
       "Proxy upstream protocol type",
       #{labels => [listener, protocol]}},
diff --git a/test/single_dc_SUITE.erl b/test/single_dc_SUITE.erl
index 1784d6a..05a3579 100644
--- a/test/single_dc_SUITE.erl
+++ b/test/single_dc_SUITE.erl
@@ -128,7 +128,7 @@ packet_too_large_case(Cfg) when is_list(Cfg) ->
     Port = ?config(mtp_port, Cfg),
     Secret = ?config(mtp_secret, Cfg),
     ErrCount = fun(Tag) ->
-                       mtp_test_metric:get_tags(count, [?APP, protocol_error, total], [Tag])
+                       mtp_test_metric:get_tags(count, [?APP, protocol_error, total], [?FUNCTION_NAME, Tag])
                end,
     OkPacket = binary:copy(<<0>>, 64),
     BigPacket = binary:copy(<<0>>, 1024 * 1024 + 1024),
@@ -333,7 +333,7 @@ replay_attack_case(Cfg) when is_list(Cfg) ->
     Seed = crypto:strong_rand_bytes(58),
     ErrCount = fun() ->
                        mtp_test_metric:get_tags(
-                         count, [?APP, protocol_error, total], [replay_session_detected])
+                         count, [?APP, protocol_error, total], [?FUNCTION_NAME, replay_session_detected])
                end,
     ?assertEqual(not_found, ErrCount()),
     Cli1 = mtp_test_client:connect(Host, Port, Seed, Secret, DcId, mtp_secure),
@@ -342,7 +342,7 @@ replay_attack_case(Cfg) when is_list(Cfg) ->
     Cli2 = mtp_test_client:connect(Host, Port, Seed, Secret, DcId, mtp_secure),
     ?assertEqual(
        ok, mtp_test_metric:wait_for_value(
-             count, [?APP, protocol_error, total], [replay_session_detected], 1, 5000),
+             count, [?APP, protocol_error, total], [?FUNCTION_NAME, replay_session_detected], 1, 5000),
        {mtp_session_storage:status(),
         sys:get_state(mtp_test_metric)}),
     ?assertEqual(1, ErrCount()),
@@ -361,7 +361,7 @@ replay_attack_server_error_case(Cfg) when is_list(Cfg) ->
     Secret = ?config(mtp_secret, Cfg),
     ErrCount = fun() ->
                        mtp_test_metric:get_tags(
-                         count, [?APP, protocol_error, total], [srv_error_filtered])
+                         count, [?APP, protocol_error, total], [?FUNCTION_NAME, srv_error_filtered])
                end,
     ?assertEqual(not_found, ErrCount()),
     Cli1 = mtp_test_client:connect(Host, Port, Secret, DcId, mtp_secure),
@@ -369,7 +369,7 @@ replay_attack_server_error_case(Cfg) when is_list(Cfg) ->
     _Cli2 = mtp_test_client:send(<<108, 254, 255, 255>>, Cli1),
     ?assertEqual(
        ok, mtp_test_metric:wait_for_value(
-             count, [?APP, protocol_error, total], [srv_error_filtered], 1, 5000),
+             count, [?APP, protocol_error, total], [?FUNCTION_NAME, srv_error_filtered], 1, 5000),
        {mtp_session_storage:status(),
         sys:get_state(mtp_test_metric)}),
     ?assertEqual(1, ErrCount()).