diff --git a/cinderlib/cinderlib.py b/cinderlib/cinderlib.py
index eb721a0..3feefed 100644
--- a/cinderlib/cinderlib.py
+++ b/cinderlib/cinderlib.py
@@ -38,7 +38,6 @@ from oslo_utils import importutils
 import urllib3
 
 import cinderlib
-from cinderlib import exception
 from cinderlib import nos_brick
 from cinderlib import objects
 from cinderlib import persistence
diff --git a/cinderlib/exception.py b/cinderlib/exception.py
index 9915740..798934f 100644
--- a/cinderlib/exception.py
+++ b/cinderlib/exception.py
@@ -21,7 +21,6 @@ VolumeNotFound = exception.VolumeNotFound
 SnapshotNotFound = exception.SnapshotNotFound
 ConnectionNotFound = exception.VolumeAttachmentNotFound
 InvalidVolume = exception.InvalidVolume
-VolumeDriverException = exception.VolumeDriverException
 
 
 class InvalidPersistence(Exception):
diff --git a/cinderlib/tests/unit/test_cinderlib.py b/cinderlib/tests/unit/test_cinderlib.py
index 30cc0c0..7211b2a 100644
--- a/cinderlib/tests/unit/test_cinderlib.py
+++ b/cinderlib/tests/unit/test_cinderlib.py
@@ -37,8 +37,7 @@ class TestCinderlib(base.BaseTest):
         driver_cfg = {'k': 'v', 'k2': 'v2', 'volume_backend_name': 'Test'}
         cinderlib.Backend.global_initialization = False
         driver = mock_import.return_value
-        driver.get_volume_stats.return_value = {
-            'pools': [{'pool_name': 'default'}]}
+        driver.capabilities = {'pools': [{'pool_name': 'default'}]}
 
         backend = objects.Backend(**driver_cfg)
 
@@ -62,7 +61,7 @@ class TestCinderlib(base.BaseTest):
         driver.set_initialized.assert_called_once_with()
         self.assertEqual(driver_cfg, backend._driver_cfg)
         self.assertIsNone(backend._volumes)
-        driver.get_volume_stats.assert_called_once_with(refresh=False)
+        driver.get_volume_stats.assert_not_called()
         self.assertEqual(('default',), backend.pool_names)
 
     @mock.patch('urllib3.disable_warnings')