diff --git a/bootstrapvz/base/__init__.py b/bootstrapvz/base/__init__.py
index 39d88a1..4bcf580 100644
--- a/bootstrapvz/base/__init__.py
+++ b/bootstrapvz/base/__init__.py
@@ -16,8 +16,12 @@ def validate_manifest(data, validator, error):
 	schema_path = os.path.normpath(os.path.join(os.path.dirname(__file__), 'manifest-schema.yml'))
 	validator(data, schema_path)
 
-	from bootstrapvz.common.tools import get_codename
-	codename = get_codename(data['system']['release'])
+	from bootstrapvz.common.releases import get_release
+	from bootstrapvz.common.releases import squeeze
+	release = get_release(data['system']['release'])
+
+	if release < squeeze:
+		error('Only Debian squeeze and later is supported', ['system', 'release'])
 
 	# Check the bootloader/partitioning configuration.
 	# Doing this via the schema is a pain and does not output a useful error message.
@@ -26,5 +30,5 @@ def validate_manifest(data, validator, error):
 		if data['volume']['partitions']['type'] == 'none':
 			error('Grub cannot boot from unpartitioned disks', ['system', 'bootloader'])
 
-		if codename == 'squeeze':
+		if release == squeeze:
 			error('Grub installation on squeeze is not supported', ['system', 'bootloader'])
diff --git a/bootstrapvz/base/bootstrapinfo.py b/bootstrapvz/base/bootstrapinfo.py
index 111c1d9..2990d24 100644
--- a/bootstrapvz/base/bootstrapinfo.py
+++ b/bootstrapvz/base/bootstrapinfo.py
@@ -31,9 +31,6 @@ class BootstrapInformation(object):
 		# The default apt mirror
 		self.apt_mirror = self.manifest.packages.get('mirror', 'http://http.debian.net/debian')
 
-		from bootstrapvz.common.tools import get_codename
-		self.release_codename = get_codename(self.manifest.system['release'])
-
 		# Create the manifest_vars dictionary
 		self.manifest_vars = self.__create_manifest_vars(self.manifest, {'apt_mirror': self.apt_mirror})
 
diff --git a/bootstrapvz/base/manifest-schema.yml b/bootstrapvz/base/manifest-schema.yml
index 229feb6..fb596eb 100644
--- a/bootstrapvz/base/manifest-schema.yml
+++ b/bootstrapvz/base/manifest-schema.yml
@@ -52,16 +52,7 @@ properties:
         type: string
         pattern: ^\S+$
       locale: {type: string}
-      release:
-        enum:
-        - squeeze
-        - wheezy
-        - jessie
-        - sid
-        - oldstable
-        - stable
-        - testing
-        - unstable
+      release: {type: string}
       timezone: {type: string}
     required:
     - release
diff --git a/bootstrapvz/base/manifest.py b/bootstrapvz/base/manifest.py
index 02ddae8..2e04d42 100644
--- a/bootstrapvz/base/manifest.py
+++ b/bootstrapvz/base/manifest.py
@@ -103,6 +103,8 @@ class Manifest(object):
 		self.image        = self.data['image']
 		self.volume       = self.data['volume']
 		self.system       = self.data['system']
+		from bootstrapvz.common.releases import get_release
+		self.release      = get_release(self.system['release'])
 		# The packages and plugins section is not required
 		self.packages     = self.data['packages'] if 'packages' in self.data else {}
 		self.plugins      = self.data['plugins'] if 'plugins' in self.data else {}
diff --git a/bootstrapvz/common/release-codenames.yml b/bootstrapvz/common/release-codenames.yml
deleted file mode 100644
index cfc2bc6..0000000
--- a/bootstrapvz/common/release-codenames.yml
+++ /dev/null
@@ -1,23 +0,0 @@
----
-# This is a mapping of Debian release names to their respective codenames
-
-unstable:  sid
-testing:   stretch
-stable:    jessie
-oldstable: wheezy
-
-jessie:  jessie
-wheezy:  wheezy
-squeeze: squeeze
-
-# The following release names are not supported, but included for completeness sake
-lenny:  lenny
-etch:   etch
-sarge:  sarge
-woody:  woody
-potato: potato
-slink:  slink
-hamm:   hamm
-bo:     bo
-rex:    rex
-buzz:   buz
diff --git a/bootstrapvz/common/releases.py b/bootstrapvz/common/releases.py
new file mode 100644
index 0000000..558b4b1
--- /dev/null
+++ b/bootstrapvz/common/releases.py
@@ -0,0 +1,68 @@
+
+
+class _Release(object):
+	def __init__(self, codename, version):
+		self.codename = codename
+		self.version = version
+
+	def __cmp__(self, other):
+		return self.version - other.version
+
+	def __str__(self):
+		return self.codename
+
+	def __getstate__(self):
+		state = self.__dict__.copy()
+		state['__class__'] = self.__module__ + '.' + self.__class__.__name__
+		return state
+
+	def __setstate__(self, state):
+		for key in state:
+			self.__dict__[key] = state[key]
+
+
+class _ReleaseAlias(_Release):
+	def __init__(self, alias, release):
+		self.alias = alias
+		self.release = release
+		super(_ReleaseAlias, self).__init__(self.release.codename, self.release.version)
+
+	def __str__(self):
+		return self.alias
+
+
+sid = _Release('sid', 10)
+stretch = _Release('stretch', 9)
+jessie = _Release('jessie', 8)
+wheezy = _Release('wheezy', 7)
+squeeze = _Release('squeeze', 6.0)
+lenny = _Release('lenny', 5.0)
+etch = _Release('etch', 4.0)
+sarge = _Release('sarge', 3.1)
+woody = _Release('woody', 3.0)
+potato = _Release('potato', 2.2)
+slink = _Release('slink', 2.1)
+hamm = _Release('hamm', 2.0)
+bo = _Release('bo', 1.3)
+rex = _Release('rex', 1.2)
+buzz = _Release('buzz', 1.1)
+
+unstable = _ReleaseAlias('unstable', sid)
+testing = _ReleaseAlias('testing', stretch)
+stable = _ReleaseAlias('stable', jessie)
+oldstable = _ReleaseAlias('oldstable', wheezy)
+
+
+def get_release(release_name):
+	"""Normalizes the release codenames
+	This allows tasks to query for release codenames rather than 'stable', 'unstable' etc.
+	"""
+	from . import releases
+	release = getattr(releases, release_name, None)
+	if release is None or not isinstance(release, _Release):
+		raise UnknownReleaseException('The release `{name}\' is unknown'.format(name=release))
+	return release
+
+
+class UnknownReleaseException(Exception):
+	pass
diff --git a/bootstrapvz/common/task_groups.py b/bootstrapvz/common/task_groups.py
index 90bff08..ab463f0 100644
--- a/bootstrapvz/common/task_groups.py
+++ b/bootstrapvz/common/task_groups.py
@@ -136,18 +136,18 @@ locale_group = [locale.LocaleBootstrapPackage,
 
 
 def get_bootloader_group(manifest):
-	from bootstrapvz.common.tools import get_codename
+	from bootstrapvz.common.releases import jessie
 	group = []
 	if manifest.system['bootloader'] == 'grub':
 		group.extend([grub.AddGrubPackage,
 		              grub.ConfigureGrub])
-		if get_codename(manifest.system['release']) in ['squeeze', 'wheezy']:
+		if manifest.release < jessie:
 			group.append(grub.InstallGrub_1_99)
 		else:
 			group.append(grub.InstallGrub_2)
 	if manifest.system['bootloader'] == 'extlinux':
 		group.append(extlinux.AddExtlinuxPackage)
-		if get_codename(manifest.system['release']) in ['squeeze', 'wheezy']:
+		if manifest.release < jessie:
 			group.extend([extlinux.ConfigureExtlinux,
 			              extlinux.InstallExtlinux])
 		else:
diff --git a/bootstrapvz/common/tasks/apt.py b/bootstrapvz/common/tasks/apt.py
index 6572674..2ee8384 100644
--- a/bootstrapvz/common/tasks/apt.py
+++ b/bootstrapvz/common/tasks/apt.py
@@ -24,12 +24,13 @@ class AddDefaultSources(Task):
 
 	@classmethod
 	def run(cls, info):
+		from bootstrapvz.common.releases import sid
 		include_src = info.manifest.packages.get('include-source-type', False)
 		components = ' '.join(info.manifest.packages.get('components', ['main']))
 		info.source_lists.add('main', 'deb     {apt_mirror} {system.release} ' + components)
 		if include_src:
 			info.source_lists.add('main', 'deb-src {apt_mirror} {system.release} ' + components)
-		if info.release_codename != 'sid':
+		if info.manifest.release != sid:
 			info.source_lists.add('main', 'deb     http://security.debian.org/  {system.release}/updates ' + components)
 			if include_src:
 				info.source_lists.add('main', 'deb-src http://security.debian.org/  {system.release}/updates ' + components)
@@ -45,10 +46,11 @@ class AddBackports(Task):
 
 	@classmethod
 	def run(cls, info):
+		from bootstrapvz.common.releases import sid
 		if info.source_lists.target_exists('{system.release}-backports'):
 			msg = ('{system.release}-backports target already exists').format(**info.manifest_vars)
 			logging.getLogger(__name__).info(msg)
-		elif info.release_codename == 'sid':
+		elif info.manifest.release == sid:
 			logging.getLogger(__name__).info('There are no backports for sid/unstable')
 		else:
 			info.source_lists.add('backports', 'deb     {apt_mirror} {system.release}-backports main')
diff --git a/bootstrapvz/common/tasks/boot.py b/bootstrapvz/common/tasks/boot.py
index 4cc121c..afa257f 100644
--- a/bootstrapvz/common/tasks/boot.py
+++ b/bootstrapvz/common/tasks/boot.py
@@ -34,9 +34,9 @@ class DisableGetTTYs(Task):
 
 	@classmethod
 	def run(cls, info):
-		# Forward compatible check for jessie,
-		# we should probably get some version numbers up in dis bitch
-		if info.release_codename in ['squeeze', 'wheezy']:
+		# Forward compatible check for jessie
+		from bootstrapvz.common.releases import jessie
+		if info.manifest.release < jessie:
 			from ..tools import sed_i
 			inittab_path = os.path.join(info.root, 'etc/inittab')
 			tty1 = '1:2345:respawn:/sbin/getty 38400 tty1'
diff --git a/bootstrapvz/common/tasks/extlinux.py b/bootstrapvz/common/tasks/extlinux.py
index 1a3b8b5..5848a43 100644
--- a/bootstrapvz/common/tasks/extlinux.py
+++ b/bootstrapvz/common/tasks/extlinux.py
@@ -27,7 +27,8 @@ class ConfigureExtlinux(Task):
 
 	@classmethod
 	def run(cls, info):
-		if info.release_codename == 'squeeze':
+		from bootstrapvz.common.releases import squeeze
+		if info.manifest.release == squeeze:
 			# On squeeze /etc/default/extlinux is generated when running extlinux-update
 			log_check_call(['chroot', info.root,
 			                'extlinux-update'])
diff --git a/bootstrapvz/common/tasks/initd.py b/bootstrapvz/common/tasks/initd.py
index c145465..5e43fa5 100644
--- a/bootstrapvz/common/tasks/initd.py
+++ b/bootstrapvz/common/tasks/initd.py
@@ -44,8 +44,9 @@ class RemoveHWClock(Task):
 
 	@classmethod
 	def run(cls, info):
+		from bootstrapvz.common.releases import squeeze
 		info.initd['disable'].append('hwclock.sh')
-		if info.release_codename == 'squeeze':
+		if info.manifest.release == squeeze:
 			info.initd['disable'].append('hwclockfirst.sh')
 
 
diff --git a/bootstrapvz/common/tasks/network.py b/bootstrapvz/common/tasks/network.py
index 6bec727..c073867 100644
--- a/bootstrapvz/common/tasks/network.py
+++ b/bootstrapvz/common/tasks/network.py
@@ -47,7 +47,7 @@ class ConfigureNetworkIF(Task):
 	def run(cls, info):
 		network_config_path = os.path.join(os.path.dirname(__file__), 'network-configuration.yml')
 		from ..tools import config_get
-		if_config = config_get(network_config_path, [info.release_codename])
+		if_config = config_get(network_config_path, [info.manifest.release.codename])
 
 		interfaces_path = os.path.join(info.root, 'etc/network/interfaces')
 		with open(interfaces_path, 'a') as interfaces:
diff --git a/bootstrapvz/common/tasks/ssh.py b/bootstrapvz/common/tasks/ssh.py
index 9ad8f21..6d3f88c 100644
--- a/bootstrapvz/common/tasks/ssh.py
+++ b/bootstrapvz/common/tasks/ssh.py
@@ -30,7 +30,8 @@ class AddSSHKeyGeneration(Task):
 		try:
 			log_check_call(['chroot', info.root,
 			                'dpkg-query', '-W', 'openssh-server'])
-			if info.release_codename == 'squeeze':
+			from bootstrapvz.common.releases import squeeze
+			if info.manifest.release == squeeze:
 				install['generate-ssh-hostkeys'] = os.path.join(init_scripts_dir, 'squeeze/generate-ssh-hostkeys')
 			else:
 				install['generate-ssh-hostkeys'] = os.path.join(init_scripts_dir, 'generate-ssh-hostkeys')
@@ -102,7 +103,8 @@ class ShredHostkeys(Task):
 	def run(cls, info):
 		ssh_hostkeys = ['ssh_host_dsa_key',
 		                'ssh_host_rsa_key']
-		if info.release_codename != 'squeeze':
+		from bootstrapvz.common.releases import wheezy
+		if info.manifest.release >= wheezy:
 			ssh_hostkeys.append('ssh_host_ecdsa_key')
 
 		private = [os.path.join(info.root, 'etc/ssh', name) for name in ssh_hostkeys]
diff --git a/bootstrapvz/common/tools.py b/bootstrapvz/common/tools.py
index 49fb425..5df7ff3 100644
--- a/bootstrapvz/common/tools.py
+++ b/bootstrapvz/common/tools.py
@@ -118,15 +118,6 @@ def config_get(path, config_path):
 	return config
 
 
-def get_codename(release):
-	"""Normalizes the release codenames
-	This allows tasks to query for release codenames rather than 'stable', 'unstable' etc.
-	"""
-	release_codenames_path = os.path.join(os.path.dirname(__file__), 'release-codenames.yml')
-	from bootstrapvz.common.tools import config_get
-	return config_get(release_codenames_path, [release])
-
-
 def copy_tree(from_path, to_path):
 	from shutil import copy
 	for abs_prefix, dirs, files in os.walk(from_path):
diff --git a/bootstrapvz/plugins/admin_user/__init__.py b/bootstrapvz/plugins/admin_user/__init__.py
index d27003f..11888de 100644
--- a/bootstrapvz/plugins/admin_user/__init__.py
+++ b/bootstrapvz/plugins/admin_user/__init__.py
@@ -13,8 +13,8 @@ def resolve_tasks(taskset, manifest):
 	if initd.AddEC2InitScripts in taskset:
 		taskset.add(tasks.AdminUserCredentials)
 
-	from bootstrapvz.common.tools import get_codename
-	if get_codename(manifest.system['release']) in ['wheezy', 'squeeze']:
+	from bootstrapvz.common.releases import jessie
+	if manifest.release < jessie:
 		taskset.update([ssh.DisableRootLogin])
 
 	taskset.update([tasks.AddSudoPackage,
diff --git a/bootstrapvz/plugins/cloud_init/__init__.py b/bootstrapvz/plugins/cloud_init/__init__.py
index f01b02f..7a59d40 100644
--- a/bootstrapvz/plugins/cloud_init/__init__.py
+++ b/bootstrapvz/plugins/cloud_init/__init__.py
@@ -13,8 +13,8 @@ def resolve_tasks(taskset, manifest):
 	from bootstrapvz.common.tasks import initd
 	from bootstrapvz.common.tasks import ssh
 
-	from bootstrapvz.common.tools import get_codename
-	if get_codename(manifest.system['release']) == 'wheezy':
+	from bootstrapvz.common.releases import wheezy
+	if manifest.release == wheezy:
 		taskset.add(apt.AddBackports)
 
 	taskset.update([tasks.SetMetadataSource,
diff --git a/bootstrapvz/plugins/cloud_init/tasks.py b/bootstrapvz/plugins/cloud_init/tasks.py
index 39bb7be..60ba51f 100644
--- a/bootstrapvz/plugins/cloud_init/tasks.py
+++ b/bootstrapvz/plugins/cloud_init/tasks.py
@@ -15,7 +15,8 @@ class AddCloudInitPackages(Task):
 	@classmethod
 	def run(cls, info):
 		target = None
-		if info.release_codename == 'wheezy':
+		from bootstrapvz.common.releases import wheezy
+		if info.manifest.release == wheezy:
 			target = '{system.release}-backports'
 		info.packages.add('cloud-init', target)
 		info.packages.add('sudo')
diff --git a/bootstrapvz/plugins/docker_daemon/__init__.py b/bootstrapvz/plugins/docker_daemon/__init__.py
index 637163e..3a72b6b 100644
--- a/bootstrapvz/plugins/docker_daemon/__init__.py
+++ b/bootstrapvz/plugins/docker_daemon/__init__.py
@@ -1,13 +1,14 @@
 import os.path
 import tasks
 from bootstrapvz.common.tasks import apt
-from bootstrapvz.common.tools import get_codename
+from bootstrapvz.common.releases import wheezy
 
 
 def validate_manifest(data, validator, error):
 	schema_path = os.path.normpath(os.path.join(os.path.dirname(__file__), 'manifest-schema.yml'))
 	validator(data, schema_path)
-	if get_codename(data['system']['release']) == 'wheezy':
+	from bootstrapvz.common.releases import get_release
+	if get_release(data['system']['release']) == wheezy:
 		# prefs is a generator of apt preferences across files in the manifest
 		prefs = (item for vals in data.get('packages', {}).get('preferences', {}).values() for item in vals)
 		if not any('linux-image' in item['package'] and 'wheezy-backports' in item['pin'] for item in prefs):
@@ -16,7 +17,7 @@ def validate_manifest(data, validator, error):
 
 
 def resolve_tasks(taskset, manifest):
-	if get_codename(manifest.system['release']) == 'wheezy':
+	if manifest.release == wheezy:
 		taskset.add(apt.AddBackports)
 	taskset.add(tasks.AddDockerDeps)
 	taskset.add(tasks.AddDockerBinary)
diff --git a/bootstrapvz/plugins/opennebula/__init__.py b/bootstrapvz/plugins/opennebula/__init__.py
index f41e21b..8681d18 100644
--- a/bootstrapvz/plugins/opennebula/__init__.py
+++ b/bootstrapvz/plugins/opennebula/__init__.py
@@ -3,7 +3,7 @@
 def resolve_tasks(taskset, manifest):
 	import tasks
 	from bootstrapvz.common.tasks import apt
-	from bootstrapvz.common.tools import get_codename
-	if get_codename(manifest.system['release']) == 'wheezy':
+	from bootstrapvz.common.releases import wheezy
+	if manifest.release == wheezy:
 		taskset.add(apt.AddBackports)
 	taskset.update([tasks.AddONEContextPackage])
diff --git a/bootstrapvz/plugins/opennebula/tasks.py b/bootstrapvz/plugins/opennebula/tasks.py
index d37e9be..33050dc 100644
--- a/bootstrapvz/plugins/opennebula/tasks.py
+++ b/bootstrapvz/plugins/opennebula/tasks.py
@@ -11,6 +11,7 @@ class AddONEContextPackage(Task):
 	@classmethod
 	def run(cls, info):
 		target = None
-		if info.release_codename == 'wheezy':
+		from bootstrapvz.common.releases import wheezy
+		if info.manifest.release == wheezy:
 			target = '{system.release}-backports'
 		info.packages.add('opennebula-context', target)
diff --git a/bootstrapvz/providers/azure/tasks/packages.py b/bootstrapvz/providers/azure/tasks/packages.py
index b7d2558..daed133 100644
--- a/bootstrapvz/providers/azure/tasks/packages.py
+++ b/bootstrapvz/providers/azure/tasks/packages.py
@@ -19,7 +19,7 @@ class DefaultPackages(Task):
 		import os.path
 		kernel_packages_path = os.path.join(os.path.dirname(__file__), 'packages-kernels.yml')
 		from bootstrapvz.common.tools import config_get
-		kernel_package = config_get(kernel_packages_path, [info.release_codename,
+		kernel_package = config_get(kernel_packages_path, [info.manifest.release.codename,
 		                                                   info.manifest.system['architecture']])
 		info.packages.add(kernel_package)
 
diff --git a/bootstrapvz/providers/ec2/tasks/network.py b/bootstrapvz/providers/ec2/tasks/network.py
index d358f2b..5c7bf81 100644
--- a/bootstrapvz/providers/ec2/tasks/network.py
+++ b/bootstrapvz/providers/ec2/tasks/network.py
@@ -13,7 +13,8 @@ class EnableDHCPCDDNS(Task):
 	def run(cls, info):
 		# The dhcp client that ships with debian sets the DNS servers per default.
 		# For dhcpcd in Wheezy and earlier we need to configure it to do that.
-		if info.release_codename not in {'jessie', 'sid'}:
+		from bootstrapvz.common.releases import wheezy
+		if info.manifest.release <= wheezy:
 			from bootstrapvz.common.tools import sed_i
 			dhcpcd = os.path.join(info.root, 'etc/default/dhcpcd')
 			sed_i(dhcpcd, '^#*SET_DNS=.*', 'SET_DNS=\'yes\'')
diff --git a/bootstrapvz/providers/ec2/tasks/packages.py b/bootstrapvz/providers/ec2/tasks/packages.py
index a85f7ed..079d112 100644
--- a/bootstrapvz/providers/ec2/tasks/packages.py
+++ b/bootstrapvz/providers/ec2/tasks/packages.py
@@ -12,7 +12,8 @@ class DefaultPackages(Task):
 	def run(cls, info):
 		info.packages.add('file')  # Needed for the init scripts
 		# isc-dhcp-client doesn't work properly with ec2
-		if info.release_codename in {'jessie', 'sid'}:
+		from bootstrapvz.common.releases import jessie
+		if info.manifest.release >= jessie:
 			info.packages.add('dhcpcd5')
 		else:
 			info.packages.add('dhcpcd')
@@ -23,6 +24,6 @@ class DefaultPackages(Task):
 		import os.path
 		kernel_packages_path = os.path.join(os.path.dirname(__file__), 'packages-kernels.yml')
 		from bootstrapvz.common.tools import config_get
-		kernel_package = config_get(kernel_packages_path, [info.release_codename,
+		kernel_package = config_get(kernel_packages_path, [info.manifest.release.codename,
 		                                                   info.manifest.system['architecture']])
 		info.packages.add(kernel_package)
diff --git a/bootstrapvz/providers/gce/tasks/packages.py b/bootstrapvz/providers/gce/tasks/packages.py
index d746af0..b67ca54 100644
--- a/bootstrapvz/providers/gce/tasks/packages.py
+++ b/bootstrapvz/providers/gce/tasks/packages.py
@@ -24,7 +24,7 @@ class DefaultPackages(Task):
 
 		kernel_packages_path = os.path.join(os.path.dirname(__file__), 'packages-kernels.yml')
 		from bootstrapvz.common.tools import config_get
-		kernel_package = config_get(kernel_packages_path, [info.release_codename,
+		kernel_package = config_get(kernel_packages_path, [info.manifest.release.codename,
 		                                                   info.manifest.system['architecture']])
 		info.packages.add(kernel_package)
 
diff --git a/bootstrapvz/providers/kvm/tasks/packages.py b/bootstrapvz/providers/kvm/tasks/packages.py
index 7498c53..30d3eda 100644
--- a/bootstrapvz/providers/kvm/tasks/packages.py
+++ b/bootstrapvz/providers/kvm/tasks/packages.py
@@ -13,6 +13,6 @@ class DefaultPackages(Task):
 		import os.path
 		kernel_packages_path = os.path.join(os.path.dirname(__file__), 'packages-kernels.yml')
 		from bootstrapvz.common.tools import config_get
-		kernel_package = config_get(kernel_packages_path, [info.release_codename,
+		kernel_package = config_get(kernel_packages_path, [info.manifest.release.codename,
 		                                                   info.manifest.system['architecture']])
 		info.packages.add(kernel_package)
diff --git a/bootstrapvz/providers/virtualbox/tasks/packages.py b/bootstrapvz/providers/virtualbox/tasks/packages.py
index ccdb419..d8a192d 100644
--- a/bootstrapvz/providers/virtualbox/tasks/packages.py
+++ b/bootstrapvz/providers/virtualbox/tasks/packages.py
@@ -13,6 +13,6 @@ class DefaultPackages(Task):
 		import os.path
 		kernel_packages_path = os.path.join(os.path.dirname(__file__), 'packages-kernels.yml')
 		from bootstrapvz.common.tools import config_get
-		kernel_package = config_get(kernel_packages_path, [info.release_codename,
+		kernel_package = config_get(kernel_packages_path, [info.manifest.release.codename,
 		                                                   info.manifest.system['architecture']])
 		info.packages.add(kernel_package)
diff --git a/tests/integration/providers/ec2/__init__.py b/tests/integration/providers/ec2/__init__.py
index f794463..39c044f 100644
--- a/tests/integration/providers/ec2/__init__.py
+++ b/tests/integration/providers/ec2/__init__.py
@@ -79,8 +79,8 @@ def run_instance(image, manifest, instance_type, ec2_connection, vpc_connection)
 			if not waituntil(lambda: instance.get_console_output().output is not None, timeout=600, interval=3):
 				raise EC2InstanceStartupException('Timeout while fetching console output')
 
-			from bootstrapvz.common.tools import get_codename
-			if get_codename(manifest.system['release']) in ['squeeze', 'wheezy']:
+			from bootstrapvz.common.releases import wheezy
+			if manifest.release <= wheezy:
 				termination_string = 'INIT: Entering runlevel: 2'
 			else:
 				termination_string = 'Debian GNU/Linux'
diff --git a/tests/integration/providers/virtualbox/__init__.py b/tests/integration/providers/virtualbox/__init__.py
index f94fb26..f9460da 100644
--- a/tests/integration/providers/virtualbox/__init__.py
+++ b/tests/integration/providers/virtualbox/__init__.py
@@ -43,7 +43,7 @@ def boot_image(manifest, build_server, bootstrap_info):
 def run_instance(image, instance_name, manifest):
 	from instance import VirtualBoxInstance
 	instance = VirtualBoxInstance(image, instance_name,
-	                              manifest.system['architecture'], manifest.system['release'])
+	                              manifest.system['architecture'], manifest.release)
 	try:
 		instance.create()
 		try:
diff --git a/tests/integration/providers/virtualbox/instance.py b/tests/integration/providers/virtualbox/instance.py
index fa520e6..5ab28da 100644
--- a/tests/integration/providers/virtualbox/instance.py
+++ b/tests/integration/providers/virtualbox/instance.py
@@ -63,8 +63,8 @@ class VirtualBoxInstance(object):
 		# Gotta figure out a more reliable way to check when the system is done booting.
 		# Maybe bootstrapped unit test images should have a startup script that issues
 		# a callback to the host.
-		from bootstrapvz.common.tools import get_codename
-		if get_codename(self.release) in ['squeeze', 'wheezy']:
+		from bootstrapvz.common.releases import wheezy
+		if self.release <= wheezy:
 			termination_string = 'INIT: Entering runlevel: 2'
 		else:
 			termination_string = 'Debian GNU/Linux'
diff --git a/tests/unit/releases_tests.py b/tests/unit/releases_tests.py
new file mode 100644
index 0000000..df7d588
--- /dev/null
+++ b/tests/unit/releases_tests.py
@@ -0,0 +1,39 @@
+from nose.tools import raises
+from bootstrapvz.common import releases
+
+
+def test_gt():
+	assert releases.wheezy > releases.squeeze
+
+
+def test_lt():
+	assert releases.wheezy < releases.stretch
+
+
+def test_eq():
+	assert releases.wheezy == releases.wheezy
+
+
+def test_neq():
+	assert releases.wheezy != releases.jessie
+
+
+def test_identity():
+	assert releases.wheezy is releases.wheezy
+
+
+def test_not_identity():
+	assert releases.wheezy is not releases.stable
+	assert releases.stable is not releases.jessie
+
+
+def test_alias():
+	assert releases.oldstable == releases.wheezy
+	assert releases.stable == releases.jessie
+	assert releases.testing == releases.stretch
+	assert releases.unstable == releases.sid
+
+
+@raises(releases.UnknownReleaseException)
+def test_bogus_releasename():
+	releases.get_release('nemo')