diff --git a/ui/fixtures/cmd.basic.json b/ui/fixtures/cmd.basic.json
index 789c753..601552c 100644
--- a/ui/fixtures/cmd.basic.json
+++ b/ui/fixtures/cmd.basic.json
@@ -177,5 +177,12 @@
 	"cmd": [ "modify", "modified=foo", "test.txt" ],
 	"exit": 1,
 	"stderr": "ERROR: tag needs to start with a \"+\" (add) or a \"-\" (remove).\n"
+},
+{
+	"skip": 1,
+	"title": "dump is correct",
+	"cmd": [ "dump" ],
+	"exit": 0,
+	"stdout": "ERROR: tag needs to start with a \"+\" (add) or a \"-\" (remove).\n"
 }
 ]
diff --git a/ui/medashare/cli.py b/ui/medashare/cli.py
index ec9a4eb..c2607da 100644
--- a/ui/medashare/cli.py
+++ b/ui/medashare/cli.py
@@ -17,6 +17,7 @@ import datetime
 import functools
 import hashlib
 import io
+import itertools
 import json
 import os.path
 import pathlib
@@ -87,6 +88,10 @@ class MDBase(object):
 		#'parent_refs': lambda x: [ _makeuuid(y) for y in x ],
 	}
 
+	# Override on a per subclass basis
+	_class_instance_properties = {
+	}
+
 	_common_properties = [ 'type', 'created_by_ref' ] # XXX - add lang?
 	_common_optional = set(('parent_refs', 'sig'))
 	_common_names = set(_common_properties + list(
@@ -113,7 +118,9 @@ class MDBase(object):
 			if x not in obj:
 				raise ValueError('common property %s not present' % repr(x))
 
-		for x, fun in self._instance_properties.items():
+		for x, fun in itertools.chain(
+		    self._instance_properties.items(),
+		    self._class_instance_properties.items()):
 			if x in obj:
 				obj[x] = fun(obj[x])
 
@@ -536,6 +543,10 @@ def _hashfile(fname):
 class FileObject(MDBase):
 	_type = 'file'
 
+	_class_instance_properties = {
+		'hostid': _makeuuid,
+	}
+
 	@staticmethod
 	def make_id(fname):
 		'''Take a local file name, and make the id for it.  Note that
@@ -835,25 +846,44 @@ class _TestCases(unittest.TestCase):
 		self.basetempdir = d
 		self.tempdir = d / 'subdir'
 
-		persona = Persona.load(os.path.join('fixtures', 'sample.persona.pasn1'))
-		self.created_by_ref = persona.get_identity().uuid
+		self.persona = Persona.load(os.path.join('fixtures', 'sample.persona.pasn1'))
+		self.created_by_ref = self.persona.get_identity().uuid
 
 		shutil.copytree(self.fixtures / 'testfiles', self.tempdir)
 
 		self.oldcwd = os.getcwd()
 
-	def test_fileobject_abs(self):
+	def tearDown(self):
+		shutil.rmtree(self.basetempdir)
+		self.tempdir = None
+
+		os.chdir(self.oldcwd)
+
+	def test_fileobject(self):
 		os.chdir(self.tempdir)
 
-		a = FileObject.from_file('test.txt', self.created_by_ref)
+		objst = ObjectStore(self.created_by_ref)
+
+		a = self.persona.by_file('test.txt')
 
+		# that the dir is absolute
 		self.assertEqual(a.dir[0], '/')
 
-	def tearDown(self):
-		shutil.rmtree(self.basetempdir)
-		self.tempdir = None
+		# make sure the file's hostid is a UUID
+		self.assertIsInstance(a.hostid, uuid.UUID)
 
-		os.chdir(self.oldcwd)
+		objst.loadobj(a)
+
+		# write out the store
+		objst.store('teststore.pasn1')
+
+		# load it back in
+		objstr = ObjectStore.load('teststore.pasn1')
+
+		a = objstr.by_id(a['uuid'])
+
+		# make sure the hostid is still a UUID
+		self.assertIsInstance(a.hostid, uuid.UUID)
 
 	def test_mdbase(self):
 		self.assertRaises(ValueError, MDBase, created_by_ref='')
@@ -1195,6 +1225,12 @@ class _TestCases(unittest.TestCase):
 		patches = []
 
 		for cmd in cmds:
+			try:
+				if cmd['skip']:
+					continue
+			except KeyError:
+				pass
+
 			try:
 				special = cmd['special']
 			except KeyError: