diff --git a/src/emqx_os_mon.erl b/src/emqx_os_mon.erl
index f8d8f41e1..a4fe7a9a7 100644
--- a/src/emqx_os_mon.erl
+++ b/src/emqx_os_mon.erl
@@ -142,7 +142,9 @@ handle_info({timeout, Timer, check}, State = #{timer := Timer,
                 true -> alarm_handler:clear_alarm(cpu_high_watermark);
                 false -> ok
             end,
-            {noreply, ensure_check_timer(State#{is_cpu_alarm_set := false})}
+            {noreply, ensure_check_timer(State#{is_cpu_alarm_set := false})};
+        _Busy ->
+            {noreply, ensure_check_timer(State)}
     end.
 
 terminate(_Reason, #{timer := Timer}) ->
diff --git a/src/emqx_vm_mon.erl b/src/emqx_vm_mon.erl
index f91fc519c..10be9d71b 100644
--- a/src/emqx_vm_mon.erl
+++ b/src/emqx_vm_mon.erl
@@ -109,7 +109,9 @@ handle_info({timeout, Timer, check}, State = #{timer := Timer,
                 true -> alarm_handler:clear_alarm(too_many_processes);
                 false -> ok
             end,
-            {noreply, ensure_check_timer(State#{is_process_alarm_set := false})}
+            {noreply, ensure_check_timer(State#{is_process_alarm_set := false})};
+        _Precent ->
+            {noreply, ensure_check_timer(State)}
     end.
 
 terminate(_Reason, #{timer := Timer}) ->