diff --git a/deps/rabbit/src/rabbit_access_control.erl b/deps/rabbit/src/rabbit_access_control.erl
index b1d6761d5b3..73f48470ba8 100644
--- a/deps/rabbit/src/rabbit_access_control.erl
+++ b/deps/rabbit/src/rabbit_access_control.erl
@@ -113,7 +113,7 @@ is_auth_backend_module_enabled(Mod) when is_atom(Mod) ->
             case rabbit_plugins:which_plugin(Mod) of
                 {ok, PluginName} ->
                     %% FIXME: The definition of an "enabled plugin" in
-                    %% `rabbit_plugins' varies from funtion to function.
+                    %% `rabbit_plugins' varies from function to function.
                     %% Sometimes, it means the "rabbitmq-plugin enable
                     %% <plugin>" was executed, sometimes it means the plugin
                     %% is running.
@@ -141,7 +141,7 @@ is_auth_backend_module_enabled(Mod) when is_atom(Mod) ->
                                "it will be skipped during "
                                "authentication/authorization",
                                [Mod, PluginName]),
-                            false
+                            is_test_auth_backend_module(Mod)
                     end;
                 {error, no_provider} ->
                     ?LOG_INFO(
@@ -150,10 +150,14 @@ is_auth_backend_module_enabled(Mod) when is_atom(Mod) ->
                        "module. Until then it will be skipped during "
                        "authentication/authorization",
                        [Mod]),
-                    false
+                    is_test_auth_backend_module(Mod)
             end
     end.
 
+is_test_auth_backend_module(Mod) ->
+    Mods = application:get_env(rabbit, test_auth_backends, []),
+    lists:member(Mod, Mods).
+
 -spec check_user_pass_login
         (rabbit_types:username(), rabbit_types:password()) ->
             {'ok', rabbit_types:user()} |
diff --git a/deps/rabbit/test/rabbit_fifo_dlx_integration_SUITE.erl b/deps/rabbit/test/rabbit_fifo_dlx_integration_SUITE.erl
index fc2ad83aa88..639403566aa 100644
--- a/deps/rabbit/test/rabbit_fifo_dlx_integration_SUITE.erl
+++ b/deps/rabbit/test/rabbit_fifo_dlx_integration_SUITE.erl
@@ -158,8 +158,12 @@ end_per_testcase(Testcase, Config) ->
     delete_queue(Ch, ?config(target_queue_6, Config)),
     #'exchange.delete_ok'{} = amqp_channel:call(Ch, #'exchange.delete'{exchange = ?config(dead_letter_exchange, Config)}),
 
-    DlxWorkers = rabbit_ct_broker_helpers:rpc_all(Config, supervisor, which_children, [rabbit_fifo_dlx_sup]),
-    ?assert(lists:all(fun(L) -> L =:= [] end, DlxWorkers)),
+    ?awaitMatch(
+       true,
+       begin
+           DlxWorkers = rabbit_ct_broker_helpers:rpc_all(Config, supervisor, which_children, [rabbit_fifo_dlx_sup]),
+           lists:all(fun(L) -> L =:= [] end, DlxWorkers)
+       end, 60000),
 
     Config1 = rabbit_ct_helpers:run_steps(
                 Config,
@@ -960,7 +964,7 @@ single_dlx_worker(Config) ->
     assert_active_dlx_workers(1, Config, Leader1).
 
 assert_active_dlx_workers(N, Config, Server) ->
-    ?assertEqual(N, length(rpc(Config, Server, supervisor, which_children, [rabbit_fifo_dlx_sup], 2000))).
+    ?awaitMatch(N, length(rpc(Config, Server, supervisor, which_children, [rabbit_fifo_dlx_sup], 2000)), 60000).
 
 declare_queue(Channel, Queue, Args) ->
     #'queue.declare_ok'{} = amqp_channel:call(Channel, #'queue.declare'{
diff --git a/deps/rabbitmq_mqtt/test/auth_SUITE.erl b/deps/rabbitmq_mqtt/test/auth_SUITE.erl
index 40bfc3f68ca..b304886a86d 100644
--- a/deps/rabbitmq_mqtt/test/auth_SUITE.erl
+++ b/deps/rabbitmq_mqtt/test/auth_SUITE.erl
@@ -251,7 +251,8 @@ auth_config(T) when T == client_id_propagation;
                     T == ssl_user_with_client_id_in_cert_san_email;
                     T == ssl_user_with_client_id_in_cert_dn ->
     {rabbit, [
-            {auth_backends, [rabbit_auth_backend_mqtt_mock]}
+            {auth_backends, [rabbit_auth_backend_mqtt_mock]},
+            {test_auth_backends, [rabbit_auth_backend_mqtt_mock]}
           ]
     };
 
diff --git a/deps/rabbitmq_mqtt/test/config_schema_SUITE.erl b/deps/rabbitmq_mqtt/test/config_schema_SUITE.erl
index 5551ac7a932..9c0604419e0 100644
--- a/deps/rabbitmq_mqtt/test/config_schema_SUITE.erl
+++ b/deps/rabbitmq_mqtt/test/config_schema_SUITE.erl
@@ -21,7 +21,12 @@ all() ->
 init_per_suite(Config) ->
     rabbit_ct_helpers:log_environment(),
     Config1 = rabbit_ct_helpers:run_setup_steps(Config),
-    rabbit_ct_config_schema:init_schemas(rabbitmq_mqtt, Config1).
+    case Config1 of
+        _ when is_list(Config1) ->
+            rabbit_ct_config_schema:init_schemas(rabbitmq_mqtt, Config1);
+        {skip, _} ->
+            Config1
+    end.
 
 
 end_per_suite(Config) ->
@@ -37,8 +42,13 @@ init_per_testcase(Testcase, Config) ->
                 Config1,
                 rabbit_ct_broker_helpers:setup_steps() ++
                     rabbit_ct_client_helpers:setup_steps()),
-    util:enable_plugin(Config2, rabbitmq_mqtt),
-    Config2.
+    case Config2 of
+        _ when is_list(Config2) ->
+            util:enable_plugin(Config2, rabbitmq_mqtt),
+            Config2;
+        {skip, _} ->
+            Config2
+    end.
 
 end_per_testcase(Testcase, Config) ->
     Config1 = rabbit_ct_helpers:run_steps(Config,