diff --git a/tests/test_awslambda/test_lambda.py b/tests/test_awslambda/test_lambda.py
index 6eaf1107c..e0e8a8205 100644
--- a/tests/test_awslambda/test_lambda.py
+++ b/tests/test_awslambda/test_lambda.py
@@ -1549,7 +1549,7 @@ def create_invalid_lambda(role):
 
 def get_role_name():
     with mock_iam():
-        iam = boto3.client("iam")
+        iam = boto3.client("iam", region_name="us-west-2")
         try:
             return iam.get_role(RoleName="my-role")["Role"]["Arn"]
         except ClientError:
diff --git a/tests/test_cloudformation/test_cloudformation_stack_crud.py b/tests/test_cloudformation/test_cloudformation_stack_crud.py
index 8ae01e7f2..c499d21bc 100644
--- a/tests/test_cloudformation/test_cloudformation_stack_crud.py
+++ b/tests/test_cloudformation/test_cloudformation_stack_crud.py
@@ -598,7 +598,7 @@ def test_create_stack_kinesis():
 
 def get_role_name():
     with mock_iam():
-        iam = boto3.client("iam")
+        iam = boto3.client("iam", region_name="us-west-2")
         return iam.create_role(
             RoleName="TestRole", AssumeRolePolicyDocument="some_policy"
         )["Role"]["Arn"]