diff --git a/big_tests/tests/bosh_SUITE.erl b/big_tests/tests/bosh_SUITE.erl
index e9c2b29dfed..840de7acee0 100644
--- a/big_tests/tests/bosh_SUITE.erl
+++ b/big_tests/tests/bosh_SUITE.erl
@@ -107,7 +107,7 @@ acks_test_cases() ->
 %%--------------------------------------------------------------------
 
 init_per_suite(Config) ->
-    instrument_helper:start(instrumentation_events() ++ negative_instrumentation_events()),
+    instrument_helper:start(instrumentation_events(), negative_instrumentation_events()),
     Config1 = dynamic_modules:save_modules(host_type(), Config),
     escalus:init_per_suite([{escalus_user_db, {module, escalus_ejabberd}} | Config1]).
 
@@ -196,7 +196,7 @@ create_and_terminate_session(Config) ->
      || {Event, Label} <- instrumentation_events(), Event =/= c2s_message_processing_time],
 
     %% Verify C2S listener is not used
-    instrument_helper:assert_not_emitted(negative_instrumentation_events(), true),
+    instrument_helper:assert_not_emitted(negative_instrumentation_events()),
 
     %% Assert the session was terminated.
     wait_for_zero_bosh_sessions().
@@ -371,6 +371,10 @@ interleave_requests(Config) ->
         escalus:assert(is_chat_message, [Msg4],
                        escalus_client:wait_for_stanza(Geralt)),
 
+        [instrument_helper:assert(Event, Label, fun(#{byte_size := BS}) -> BS > 0;
+                                                   (#{time := Time}) -> Time > 0 end)
+         || {Event, Label} <- instrumentation_events()],
+
         true = is_bosh_connected(Carol)
     end).
 
diff --git a/big_tests/tests/instrument_helper.erl b/big_tests/tests/instrument_helper.erl
index 84b39c43e17..03ec6058422 100644
--- a/big_tests/tests/instrument_helper.erl
+++ b/big_tests/tests/instrument_helper.erl
@@ -4,9 +4,9 @@
 -module(instrument_helper).
 
 -export([declared_events/1, declared_events/2,
-         start/1, stop/0,
+         start/1, start/2, stop/0,
          assert/3, assert/4,
-         assert_not_emitted/2, assert_not_emitted/3,
+         assert_not_emitted/1, assert_not_emitted/2,
          wait_for/2, wait_for_new/2,
          lookup/2, take/2]).
 
@@ -34,25 +34,30 @@ declared_events(Module, Args) ->
     Specs = rpc(mim(), Module, instrumentation, Args),
     [{Event, Labels} || {Event, Labels, _Config} <- Specs].
 
-%% @doc Only `DeclaredEvents' will be logged, and can be tested with `assert/3'
--spec start([{event_name(), labels()} | module()]) -> ok.
+-spec start([{event_name(), labels()}]) -> ok.
 start(DeclaredEvents) ->
+    start(DeclaredEvents, []).
+
+%% @doc Only `DeclaredEvents' will be logged, and can be tested with `assert/3'
+-spec start([{event_name(), labels()}], [{event_name(), labels()}]) -> ok.
+start(DeclaredEvents, NegativeEvents) ->
     mongoose_helper:inject_module(ets_helper),
     mongoose_helper:inject_module(?HANDLER_MODULE),
     ets_helper:new(?STATUS_TABLE),
+    [ets:insert(?STATUS_TABLE, {Event, negative}) || Event <- NegativeEvents],
     [ets:insert(?STATUS_TABLE, {Event, untested}) || Event <- DeclaredEvents],
     rpc(mim(), mongoose_instrument, add_handler,
-        [event_table, #{declared_events => DeclaredEvents}]).
+        [event_table, #{declared_events => DeclaredEvents ++ NegativeEvents}]).
 
 -spec stop() -> ok.
 stop() ->
-    #{tested := Tested, untested := Untested} = classify_events(),
+    #{tested := Tested, untested := Untested, negative := Negative} = classify_events(),
     ets_helper:delete(?STATUS_TABLE),
     Logged = rpc(mim(), ?HANDLER_MODULE, all_keys, []),
     rpc(mim(), mongoose_instrument, remove_handler, [event_table]),
     ct:log("Tested instrumentation events:~n~p", [lists:sort(Tested)]),
-    verify_unlogged(Untested -- Logged),
-    verify_logged_but_untested(Logged -- Tested).
+    verify_unlogged((Untested -- Logged) -- Negative),
+    verify_logged_but_untested((Logged -- Tested) -- Negative).
 
 -spec assert(event_name(), labels(), fun((measurements()) -> boolean())) -> ok.
 assert(EventName, Labels, CheckF) ->
@@ -75,17 +80,16 @@ assert(EventName, Labels, MeasurementsList, CheckF) ->
             event_tested(EventName, Labels)
     end.
 
-assert_not_emitted(EventName, Labels, MarkAsTested) ->
+assert_not_emitted(EventName, Labels) ->
     case lookup(EventName, Labels) of
         [] ->
-            event_tested(EventName, Labels);
+            ok;
         Events ->
             ct:fail("Measurements emitted but should not ~p", [Events])
     end.
 
-assert_not_emitted(Events, MarkAsTested) ->
-    [assert_not_emitted(Event, Label, MarkAsTested)
-     || {Event, Label} <- Events].
+assert_not_emitted(Events) ->
+    [assert_not_emitted(Event, Label) || {Event, Label} <- Events].
 
 %% @doc Remove previous events, and wait for a new one. Use for probes only.
 -spec wait_for_new(event_name(), labels()) -> [measurements()].
@@ -129,7 +133,7 @@ event_tested(EventName, Labels) ->
     ok.
 
 classify_events() ->
-    ets:foldl(fun classify_event/2, #{tested => [], untested => []}, ?STATUS_TABLE).
+    ets:foldl(fun classify_event/2, #{tested => [], untested => [], negative => []}, ?STATUS_TABLE).
 
 classify_event({Event, Status}, M) ->
     M#{Status => [Event | maps:get(Status, M)]}.
diff --git a/big_tests/tests/mim_c2s_SUITE.erl b/big_tests/tests/mim_c2s_SUITE.erl
index b91090040cb..0b584d04206 100644
--- a/big_tests/tests/mim_c2s_SUITE.erl
+++ b/big_tests/tests/mim_c2s_SUITE.erl
@@ -129,7 +129,7 @@ two_users_can_log_and_chat(Config) ->
         [instrument_helper:assert(Event, Label, fun(#{byte_size := BS}) -> BS > 0;
                                                    (#{time := Time}) -> Time > 0 end)
          || {Event, Label} <- tcp_instrumentation_events() ++ common_instrumentation_events()],
-        instrument_helper:assert_not_emitted(tls_instrumentation_events(), true)
+        instrument_helper:assert_not_emitted(tls_instrumentation_events())
     end).
 
 too_big_stanza_is_rejected(Config) ->
@@ -253,4 +253,6 @@ tls_instrumentation_events() ->
 
 common_instrumentation_events() ->
     HostType = domain_helper:host_type(),
-    [{c2s_message_processing_time, #{host_type => HostType}}].
+    [{c2s_message_processing_time, #{host_type => HostType}},
+     {xmpp_stanza_size_received, #{}},
+     {xmpp_stanza_size_sent, #{}}].
diff --git a/big_tests/tests/websockets_SUITE.erl b/big_tests/tests/websockets_SUITE.erl
index a9b42a7a8ae..80cf94d8541 100644
--- a/big_tests/tests/websockets_SUITE.erl
+++ b/big_tests/tests/websockets_SUITE.erl
@@ -54,7 +54,7 @@ suite() ->
 %%--------------------------------------------------------------------
 
 init_per_suite(Config) ->
-    instrument_helper:start(instrumentation_events() ++ negative_instrumentation_events()),
+    instrument_helper:start(instrumentation_events(), negative_instrumentation_events()),
     Config1 = escalus:init_per_suite(Config),
     Config2 = setup_listeners(Config1),
     escalus:create_users(Config2, escalus:get_users([alice, geralt, geralt_s, carol])).
@@ -117,7 +117,7 @@ metrics_test(Config) ->
          || {Event, Label} <- instrumentation_events()],
 
         %% Verify C2S listener is not used
-        instrument_helper:assert_not_emitted(negative_instrumentation_events(), true),
+        instrument_helper:assert_not_emitted(negative_instrumentation_events()),
         ok
         end).