diff --git a/cleancloud/providers/aws/rules/rds_idle.py b/cleancloud/providers/aws/rules/rds_idle.py
index 83c3091..bc47c2e 100644
--- a/cleancloud/providers/aws/rules/rds_idle.py
+++ b/cleancloud/providers/aws/rules/rds_idle.py
@@ -1,5 +1,5 @@
 from datetime import datetime, timedelta, timezone
-from typing import List
+from typing import List, Optional
 
 import boto3
 from botocore.exceptions import ClientError
@@ -236,7 +236,7 @@ def _estimate_monthly_cost(instance_class: str, multi_az: bool) -> str:
     return "Cost varies by instance class (region dependent)"
 
 
-def _estimate_monthly_cost_usd(instance_class: str, multi_az: bool) -> float | None:
+def _estimate_monthly_cost_usd(instance_class: str, multi_az: bool) -> Optional[float]:
     """Numeric monthly cost estimate for aggregation."""
     cost_map = {
         "db.t3.micro": 12,
diff --git a/cleancloud/providers/aws/session.py b/cleancloud/providers/aws/session.py
index 343ebbe..38f18b9 100644
--- a/cleancloud/providers/aws/session.py
+++ b/cleancloud/providers/aws/session.py
@@ -1,8 +1,10 @@
+from typing import Optional
+
 import boto3
 from boto3.session import Session
 
 
-def create_aws_session(profile: str | None, region: str) -> Session:
+def create_aws_session(profile: Optional[str], region: str) -> Session:
     if profile:
         return boto3.Session(profile_name=profile, region_name=region)
 
diff --git a/cleancloud/providers/azure/rules/sql_database_idle.py b/cleancloud/providers/azure/rules/sql_database_idle.py
index f7484a4..b05ac1c 100644
--- a/cleancloud/providers/azure/rules/sql_database_idle.py
+++ b/cleancloud/providers/azure/rules/sql_database_idle.py
@@ -220,7 +220,7 @@ def _estimate_monthly_cost(sku_name: str) -> str:
     return "Cost varies by SKU (region dependent)"
 
 
-def _estimate_monthly_cost_usd(sku_name: str) -> float | None:
+def _estimate_monthly_cost_usd(sku_name: str) -> Optional[float]:
     """Numeric monthly cost estimate for aggregation."""
     if not sku_name:
         return None