obj.diff

diff --git a/cinder/objects/volume.py b/cinder/objects/volume.py
index d50175e..3556ceb 100644
--- a/cinder/objects/volume.py
+++ b/cinder/objects/volume.py
@@ -455,6 +455,6 @@ class VolumeList(base.ObjectListBase, base.CinderObject):
                                                limit, sort_keys=sort_keys,
                                                sort_dirs=sort_dirs,
                                                filters=filters, offset=offset)
-        expected_attrs = ['admin_metadata', 'metadata']
+        expected_attrs = ['admin_metadata', 'metadata', 'volume_type']
         return base.obj_make_list(context, cls(context), objects.Volume,
                                   volumes, expected_attrs=expected_attrs)