diff --git a/taskflow/engines/action_engine/engine.py b/taskflow/engines/action_engine/engine.py
index bed43e8e..5eb4fee6 100644
--- a/taskflow/engines/action_engine/engine.py
+++ b/taskflow/engines/action_engine/engine.py
@@ -312,7 +312,7 @@ class _ExecutorTextMatch(collections.namedtuple('_ExecutorTextMatch',
 class ParallelActionEngine(ActionEngine):
     """Engine that runs tasks in parallel manner.
 
-    Supported keyword arguments:
+    Supported option keys:
 
     * ``executor``: a object that implements a :pep:`3148` compatible executor
       interface; it will be used for scheduling tasks. The following