diff --git a/core/queue_db.py b/core/queue_db.py
index bf63083..67ab215 100644
--- a/core/queue_db.py
+++ b/core/queue_db.py
@@ -1,13 +1,15 @@
 """Oracle ADB connection pool and CRUD operations for knowledge_queue."""
 
+from __future__ import annotations
+
 import json
 import os
 from contextlib import contextmanager
-from typing import Generator
+from typing import Generator, Optional
 
 import oracledb
 
-_pool: oracledb.ConnectionPool | None = None
+_pool: Optional[oracledb.ConnectionPool] = None
 
 
 def _get_pool() -> oracledb.ConnectionPool:
diff --git a/core/vector.py b/core/vector.py
index 8c4ff4f..5b53891 100644
--- a/core/vector.py
+++ b/core/vector.py
@@ -1,9 +1,11 @@
 """Embedding generation and Oracle vector store insertion."""
 
+from __future__ import annotations
+
 import array
 import os
 from contextlib import contextmanager
-from typing import Generator
+from typing import Generator, Optional
 
 import oci
 import oracledb
@@ -14,7 +16,7 @@ from oci.generative_ai_inference.models import (
 )
 
 # Reuse same pool as queue_db but connect to same ADB instance
-_pool: oracledb.ConnectionPool | None = None
+_pool: Optional[oracledb.ConnectionPool] = None
 
 
 def _get_pool() -> oracledb.ConnectionPool: