diff --git a/tests/unit/test_client.py b/tests/unit/test_client.py
index 9c260c5f95..40d10de9df 100644
--- a/tests/unit/test_client.py
+++ b/tests/unit/test_client.py
@@ -88,7 +88,9 @@ def _constructor_test_helper(
 
         self.assertIs(client._credentials, expected_creds)
         if expected_scopes is not None:
-            creds.with_scopes.assert_called_once_with(expected_scopes)
+            creds.with_scopes.assert_called_once_with(
+                expected_scopes, default_scopes=None
+            )
 
         self.assertEqual(client.project, self.PROJECT)
         self.assertIs(client._client_info, expected_client_info)
@@ -235,7 +237,9 @@ def test_instance_admin_api(self, mock_em):
             credentials=mock.ANY, client_info=client_info, client_options=client_options
         )
 
-        credentials.with_scopes.assert_called_once_with(expected_scopes)
+        credentials.with_scopes.assert_called_once_with(
+            expected_scopes, default_scopes=None
+        )
 
     @mock.patch("google.cloud.spanner_v1.client._get_spanner_emulator_host")
     def test_instance_admin_api_emulator_env(self, mock_em):
@@ -333,7 +337,9 @@ def test_database_admin_api(self, mock_em):
             credentials=mock.ANY, client_info=client_info, client_options=client_options
         )
 
-        credentials.with_scopes.assert_called_once_with(expected_scopes)
+        credentials.with_scopes.assert_called_once_with(
+            expected_scopes, default_scopes=None
+        )
 
     @mock.patch("google.cloud.spanner_v1.client._get_spanner_emulator_host")
     def test_database_admin_api_emulator_env(self, mock_em):