diff --git a/core/workflow.py b/core/workflow.py
index 0676a2d..fa325d9 100755
--- a/core/workflow.py
+++ b/core/workflow.py
@@ -10,7 +10,7 @@ import asyncio
 import os
 import uuid
 from enum import Enum
-from typing import Optional, Dict, Callable, Awaitable, Any
+from typing import Optional, Dict, Callable, Awaitable, Any, List
 from datetime import datetime
 from dataclasses import dataclass, field