diff --git a/cdk/lambdas/wdiv-s3-trigger/tests/test_handler.py b/cdk/lambdas/wdiv-s3-trigger/tests/test_handler.py
index 29e021dcf2..a4629c6edb 100644
--- a/cdk/lambdas/wdiv-s3-trigger/tests/test_handler.py
+++ b/cdk/lambdas/wdiv-s3-trigger/tests/test_handler.py
@@ -6,10 +6,12 @@
 from unittest import TestCase
 
 import boto3
+import moto
 import responses
 from botocore.exceptions import ClientError
 from moto import mock_s3, mock_ses
 from moto.ses import ses_backends
+from moto.s3 import responses as moto_s3_responses
 
 from trigger.handler import main
 
@@ -54,6 +56,8 @@
 }"""
 )
 
+os.environ["AWS_DEFAULT_REGION"] = moto_s3_responses.DEFAULT_REGION_NAME = "eu-west-1"
+
 
 class HandlerTests(TestCase):
     """