diff --git a/apps/emqx_modules/test/emqx_delayed_SUITE.erl b/apps/emqx_modules/test/emqx_delayed_SUITE.erl
index ab35e37dc..ffea436bb 100644
--- a/apps/emqx_modules/test/emqx_delayed_SUITE.erl
+++ b/apps/emqx_modules/test/emqx_delayed_SUITE.erl
@@ -229,6 +229,14 @@ t_banned_delayed(_) ->
     }),
 
     snabbkaffe:start_trace(),
+    {ok, SubRef} =
+        snabbkaffe:subscribe(
+            ?match_event(#{?snk_kind := ignore_delayed_message_publish}),
+            _NEvents = 2,
+            _Timeout = 10000,
+            0
+        ),
+
     lists:foreach(
         fun(ClientId) ->
             Msg = emqx_message:make(ClientId, <<"$delayed/1/bc">>, <<"payload">>),
@@ -237,8 +245,7 @@ t_banned_delayed(_) ->
         [ClientId1, ClientId1, ClientId1, ClientId2, ClientId2]
     ),
 
-    timer:sleep(2000),
-    Trace = snabbkaffe:collect_trace(),
+    {ok, Trace} = snabbkaffe:receive_events(SubRef),
     snabbkaffe:stop(),
     emqx_banned:delete(Who),
     mnesia:clear_table(emqx_delayed),
diff --git a/apps/emqx_retainer/test/emqx_retainer_SUITE.erl b/apps/emqx_retainer/test/emqx_retainer_SUITE.erl
index 845f07802..09d1f77da 100644
--- a/apps/emqx_retainer/test/emqx_retainer_SUITE.erl
+++ b/apps/emqx_retainer/test/emqx_retainer_SUITE.erl
@@ -687,11 +687,19 @@ t_deliver_when_banned(_) ->
     }),
 
     timer:sleep(100),
-    snabbkaffe:start_trace(),
-    {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained/+">>, [{qos, 0}, {rh, 0}]),
-    timer:sleep(500),
 
-    Trace = snabbkaffe:collect_trace(),
+    snabbkaffe:start_trace(),
+    {ok, SubRef} =
+        snabbkaffe:subscribe(
+            ?match_event(#{?snk_kind := ignore_retained_message_deliver}),
+            _NEvents = 3,
+            _Timeout = 10000,
+            0
+        ),
+
+    {ok, #{}, [0]} = emqtt:subscribe(C1, <<"retained/+">>, [{qos, 0}, {rh, 0}]),
+
+    {ok, Trace} = snabbkaffe:receive_events(SubRef),
     ?assertEqual(3, length(?of_kind(ignore_retained_message_deliver, Trace))),
     snabbkaffe:stop(),
     emqx_banned:delete(Who),