diff --git a/backend/src/ea_chatbot/history/utils.py b/backend/src/ea_chatbot/history/utils.py
index 450ebba..3d3400b 100644
--- a/backend/src/ea_chatbot/history/utils.py
+++ b/backend/src/ea_chatbot/history/utils.py
@@ -1,8 +1,9 @@
+"""Utility functions for history management."""
 from typing import List
 from langchain_core.messages import BaseMessage, HumanMessage, AIMessage, SystemMessage
 from ea_chatbot.history.models import Message
 
-def map_db_messages_to_langchain(db_messages: List[Message]) -> List[BaseMessage]:
+def map_db_messages_to_langchain(db_messages: List[Message]) -> List[BaseMessage] :
     """
     Converts a list of database Message models to LangChain BaseMessage objects.