diff --git a/xenserver/destroy_cached_images.py b/xenserver/destroy_cached_images.py
index 8bd77ec..fa71c0a 100644
--- a/xenserver/destroy_cached_images.py
+++ b/xenserver/destroy_cached_images.py
@@ -25,7 +25,6 @@ POSSIBLE_TOPDIR = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
 if os.path.exists(os.path.join(POSSIBLE_TOPDIR, 'nova', '__init__.py')):
     sys.path.insert(0, POSSIBLE_TOPDIR)
 
-from nova import config
 from nova import config
 from nova.openstack.common import cfg
 from nova.openstack.common import log as logging
diff --git a/xenserver/vm_vdi_cleaner.py b/xenserver/vm_vdi_cleaner.py
index 0371aef..d0ec2d6 100755
--- a/xenserver/vm_vdi_cleaner.py
+++ b/xenserver/vm_vdi_cleaner.py
@@ -27,7 +27,6 @@ if os.path.exists(os.path.join(possible_topdir, "nova", "__init__.py")):
         sys.path.insert(0, possible_topdir)
 
 
-from nova import config
 from nova import context
 from nova import db
 from nova import exception
@@ -37,6 +36,7 @@ from nova.virt.xenapi import driver as xenapi_driver
 
 
 CONF = cfg.CONF
+CONF.import_opt('zombie_instance_updated_at_window', 'nova.config')
 CONF.import_opt("resize_confirm_window", "nova.compute.manager")