diff --git a/backend/common/serializers.py b/backend/common/serializers.py
index a22eac5e..faac033e 100644
--- a/backend/common/serializers.py
+++ b/backend/common/serializers.py
@@ -69,6 +69,7 @@ class NotificationSerializer(serializers.Serializer):
     level = serializers.ChoiceField(choices=["info", "error"])
     messages = serializers.ListField(child=serializers.CharField())
     progress = serializers.FloatField(required=False)
+    command = serializers.ChoiceField(choices=["STOP", "KILL"], required=False)
 
 
 class NotificationQueryFilterSerializer(serializers.Serializer):
diff --git a/backend/task/tasks.py b/backend/task/tasks.py
index 525938b4..d879cb9e 100644
--- a/backend/task/tasks.py
+++ b/backend/task/tasks.py
@@ -79,7 +79,7 @@ class BaseTask(Task):
         message.update({"level": level, "id": task_id})
         task_result = TaskManager().get_task(task_id)
         if task_result:
-            command = task_result.get("command", False)
+            command = task_result.get("command", None)
             message.update({"command": command})
 
         key = f"message:{message.get('group')}:{task_id.split('-')[0]}"