diff --git a/nova/tests/virt/vmwareapi/test_imagecache.py b/nova/tests/virt/vmwareapi/test_imagecache.py
index d5926c092b8b..fd4090f3e2ea 100644
--- a/nova/tests/virt/vmwareapi/test_imagecache.py
+++ b/nova/tests/virt/vmwareapi/test_imagecache.py
@@ -104,26 +104,18 @@ class ImageCacheManagerTestCase(test.NoDBTestCase):
         self.assertEqual(self._time, t)
 
     def test_get_ds_browser(self):
-        def fake_get_dynamic_property(vim, mobj, type, property_name):
-            self.assertEqual('Datastore', type)
-            self.assertEqual('browser', property_name)
-            self.fake_called += 1
-            return 'fake-ds-browser'
-
-        with contextlib.nested(
-            mock.patch.object(vim_util, 'get_dynamic_property',
-                              fake_get_dynamic_property)
-        ):
-            self.fake_called = 0
-            self.assertEqual({}, self._imagecache._ds_browser)
-            browser = self._imagecache._get_ds_browser('fake-ds-ref')
-            self.assertEqual('fake-ds-browser', browser)
-            self.assertEqual({'fake-ds-ref': 'fake-ds-browser'},
-                             self._imagecache._ds_browser)
-            self.assertEqual(1, self.fake_called)
-            browser = self._imagecache._get_ds_browser('fake-ds-ref')
-            self.assertEqual('fake-ds-browser', browser)
-            self.assertEqual(1, self.fake_called)
+        cache = self._imagecache._ds_browser
+        ds_browser = mock.Mock()
+        moref = fake.ManagedObjectReference('datastore-100')
+        self.assertIsNone(cache.get(moref.value))
+        mock_get_method = mock.Mock(return_value=ds_browser)
+        with mock.patch.object(vim_util, 'get_dynamic_property',
+                               mock_get_method):
+            ret = self._imagecache._get_ds_browser(moref)
+            mock_get_method.assert_called_once_with(mock.ANY, moref,
+                                                    'Datastore', 'browser')
+            self.assertIs(ds_browser, ret)
+            self.assertIs(ds_browser, cache.get(moref.value))
 
     def test_list_base_images(self):
         def fake_get_dynamic_property(vim, mobj, type, property_name):
@@ -140,7 +132,8 @@ class ImageCacheManagerTestCase(test.NoDBTestCase):
             mock.patch.object(ds_util, 'get_sub_folders',
                               fake_get_sub_folders)
         ) as (_get_dynamic, _get_sub_folders):
-            datastore = {'name': 'ds', 'ref': 'fake-ds-ref'}
+            fake_ds_ref = fake.ManagedObjectReference('fake-ds-ref')
+            datastore = {'name': 'ds', 'ref': fake_ds_ref}
             ds_path = ds_util.build_datastore_path(datastore['name'],
                                                    'base_folder')
             images = self._imagecache._list_datastore_images(
diff --git a/nova/tests/virt/vmwareapi/test_vmops.py b/nova/tests/virt/vmwareapi/test_vmops.py
index c0e34d49929e..38d83c969c57 100644
--- a/nova/tests/virt/vmwareapi/test_vmops.py
+++ b/nova/tests/virt/vmwareapi/test_vmops.py
@@ -522,3 +522,17 @@ class VMwareVMOpsTestCase(test.NoDBTestCase):
             # we don't care what the log message is, we just want to make sure
             # our stub method is called which asserts the password is scrubbed
             self.assertTrue(debug_mock.called)
+
+    def test_get_ds_browser(self):
+        cache = self._vmops._datastore_browser_mapping
+        ds_browser = mock.Mock()
+        moref = vmwareapi_fake.ManagedObjectReference('datastore-100')
+        self.assertIsNone(cache.get(moref.value))
+        mock_call_method = mock.Mock(return_value=ds_browser)
+        with mock.patch.object(self._session, '_call_method',
+                               mock_call_method):
+            ret = self._vmops._get_ds_browser(moref)
+            mock_call_method.assert_called_once_with(vim_util,
+                'get_dynamic_property', moref, 'Datastore', 'browser')
+            self.assertIs(ds_browser, ret)
+            self.assertIs(ds_browser, cache.get(moref.value))
diff --git a/nova/virt/vmwareapi/imagecache.py b/nova/virt/vmwareapi/imagecache.py
index dd9972de7752..0e5a94949615 100644
--- a/nova/virt/vmwareapi/imagecache.py
+++ b/nova/virt/vmwareapi/imagecache.py
@@ -105,12 +105,12 @@ class ImageCacheManager(imagecache.ImageCacheManager):
         return timeutils.parse_strtime(ts, fmt=TIMESTAMP_FORMAT)
 
     def _get_ds_browser(self, ds_ref):
-        ds_browser = self._ds_browser.get(ds_ref)
+        ds_browser = self._ds_browser.get(ds_ref.value)
         if not ds_browser:
             ds_browser = vim_util.get_dynamic_property(
                     self._session._get_vim(), ds_ref,
                     "Datastore", "browser")
-            self._ds_browser[ds_ref] = ds_browser
+            self._ds_browser[ds_ref.value] = ds_browser
         return ds_browser
 
     def _list_datastore_images(self, ds_path, datastore):
diff --git a/nova/virt/vmwareapi/vmops.py b/nova/virt/vmwareapi/vmops.py
index 971eb4a24563..35c1c9e4a66f 100755
--- a/nova/virt/vmwareapi/vmops.py
+++ b/nova/virt/vmwareapi/vmops.py
@@ -1387,12 +1387,12 @@ class VMwareVMOps(object):
                   instance=instance)
 
     def _get_ds_browser(self, ds_ref):
-        ds_browser = self._datastore_browser_mapping.get(ds_ref)
+        ds_browser = self._datastore_browser_mapping.get(ds_ref.value)
         if not ds_browser:
             ds_browser = self._session._call_method(
                 vim_util, "get_dynamic_property", ds_ref, "Datastore",
                 "browser")
-            self._datastore_browser_mapping[ds_ref] = ds_browser
+            self._datastore_browser_mapping[ds_ref.value] = ds_browser
         return ds_browser
 
     def get_datacenter_ref_and_name(self, ds_ref):