diff --git a/metagpt/actions/write_teaching_plan.py b/metagpt/actions/write_teaching_plan.py
index bd6e96956..10fc2863f 100644
--- a/metagpt/actions/write_teaching_plan.py
+++ b/metagpt/actions/write_teaching_plan.py
@@ -21,7 +21,7 @@ class TeachingPlanRequirement(Action):
 class WriteTeachingPlanPart(Action):
     """Write Teaching Plan Part"""
 
-    def __init__(self, name: str = '', context=None, llm: LLM = None, topic="", language="Chinese"):
+    def __init__(self, name: str = "", context=None, llm: LLM = None, topic: str = "", language: str = "Chinese"):
         """
 
         Args: