diff --git a/hooks/utils.py b/hooks/utils.py
index 2acad66d..ea218860 100644
--- a/hooks/utils.py
+++ b/hooks/utils.py
@@ -19,7 +19,8 @@ from charmhelpers.core.hookenv import (
     cached,
     config,
     network_get_primary_address,
-    log, DEBUG,
+    log,
+    DEBUG,
     status_set,
 )
 from charmhelpers.core import unitdata
@@ -29,7 +30,8 @@ from charmhelpers.fetch import (
 )
 
 from charmhelpers.core.host import (
-    lsb_release
+    lsb_release,
+    CompareHostReleases,
 )
 
 from charmhelpers.contrib.network.ip import (
@@ -163,7 +165,8 @@ def get_network_addrs(config_opt):
 
 def assert_charm_supports_ipv6():
     """Check whether we are able to support charms ipv6."""
-    if lsb_release()['DISTRIB_CODENAME'].lower() < "trusty":
+    _release = lsb_release()['DISTRIB_CODENAME'].lower()
+    if CompareHostReleases(_release) < "trusty":
         raise Exception("IPv6 is not supported in the charms for Ubuntu "
                         "versions less than Trusty 14.04")
 
diff --git a/lib/ceph/__init__.py b/lib/ceph/__init__.py
index 7acbc521..32c7ce6c 100644
--- a/lib/ceph/__init__.py
+++ b/lib/ceph/__init__.py
@@ -38,7 +38,9 @@ from charmhelpers.core.host import (
     owner,
     service_restart,
     service_start,
-    service_stop)
+    service_stop,
+    CompareHostReleases,
+)
 from charmhelpers.core.hookenv import (
     cached,
     config,
@@ -46,21 +48,28 @@ from charmhelpers.core.hookenv import (
     status_set,
     DEBUG,
     ERROR,
-    WARNING)
+    WARNING,
+)
 from charmhelpers.fetch import (
     apt_cache,
-    add_source, apt_install, apt_update)
+    add_source,
+    apt_install,
+    apt_update,
+)
 from charmhelpers.contrib.storage.linux.ceph import (
     monitor_key_set,
     monitor_key_exists,
     monitor_key_get,
-    get_mon_map)
+    get_mon_map,
+)
 from charmhelpers.contrib.storage.linux.utils import (
     is_block_device,
     zap_disk,
-    is_device_mounted)
+    is_device_mounted,
+)
 from charmhelpers.contrib.openstack.utils import (
-    get_os_codename_install_source)
+    get_os_codename_install_source,
+)
 
 from ceph.ceph_helpers import check_output
 
@@ -1180,7 +1189,7 @@ def upgrade_key_caps(key, caps):
 
 @cached
 def systemd():
-    return (lsb_release()['DISTRIB_CODENAME'] >= 'vivid')
+    return CompareHostReleases(lsb_release()['DISTRIB_CODENAME']) >= 'vivid'
 
 
 def bootstrap_monitor_cluster(secret):
diff --git a/tox.ini b/tox.ini
index 6f1aeace..7c2936e3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,7 +14,7 @@ install_command =
   pip install --allow-unverified python-apt {opts} {packages}
 commands = ostestr {posargs}
 whitelist_externals = juju
-passenv = HOME TERM AMULET_* CS_API_URL
+passenv = HOME TERM AMULET_* CS_API_*
 
 [testenv:py27]
 basepython = python2.7