diff --git a/libs/lib/xaal/lib/engine.py b/libs/lib/xaal/lib/engine.py
index 1a5fc608ecc862d7ece1ffc030091e11b53ae6cb..4c6ec7fca87a1f3d0accb7da87016992f5605640 100644
--- a/libs/lib/xaal/lib/engine.py
+++ b/libs/lib/xaal/lib/engine.py
@@ -25,8 +25,6 @@ import typing
 from enum import Enum
 from typing import Optional
 
-
-
 from .config import config
 from . import core
 from .exceptions import CallbackError, MessageParserError, XAALError
@@ -135,11 +133,11 @@ class Engine(core.EngineMixin):
                 * error returned on the xAAL bus
         """
         if msg.action is None:
-            return # should not happen, but pyright need this check
+            return  # should not happen, but pyright need this check
 
         try:
             result = run_action(msg, target)
-            if result:
+            if result is not None:
                 self.send_reply(dev=target, targets=[msg.source], action=msg.action, body=result)
         except CallbackError as e:
             self.send_error(target, e.code, e.description)