diff --git a/tests/unit/operations_v1/test_operations_rest_client.py b/tests/unit/operations_v1/test_operations_rest_client.py
index 68bd9287..955b1d1b 100644
--- a/tests/unit/operations_v1/test_operations_rest_client.py
+++ b/tests/unit/operations_v1/test_operations_rest_client.py
@@ -30,6 +30,7 @@
 from google.api_core import gapic_v1
 from google.api_core.operations_v1 import AbstractOperationsClient
 
+import google.auth
 from google.api_core.operations_v1 import pagers
 from google.api_core.operations_v1 import pagers_async
 from google.api_core.operations_v1 import transports