diff --git a/src/ska_tango_base/base/task_queue_manager.py b/src/ska_tango_base/base/task_queue_manager.py
index 81737a8afb000ac9679d1f8878855d7a5a7b3acb..1c56b9657e37e55bebab0b8b7309440850aba689 100644
--- a/src/ska_tango_base/base/task_queue_manager.py
+++ b/src/ska_tango_base/base/task_queue_manager.py
@@ -462,7 +462,7 @@ class QueueManager:
         self._property_update_lock = threading.Lock()
         self._logger = logger if logger else logging.getLogger(__name__)
 
-        self._task_result: Union[Tuple[str, str, str], Tuple[()]] = ("", "", "")
+        self._task_result: Tuple[str, str, str] = ("", "", "")
         self._tasks_in_queue: Dict[str, str] = {}  # unique_id, task_name
         self._task_status: Dict[str, str] = {}  # unique_id, status
         self._threads = []