diff --git a/acme/acme/client.py b/acme/acme/client.py
index 03480c5da..a61efe6c4 100644
--- a/acme/acme/client.py
+++ b/acme/acme/client.py
@@ -753,7 +753,7 @@ class BackwardsCompatibleClientV2(object):
                     time.sleep(1)
 
             if chain is None:
-                raise errors.Error(
+                raise errors.TimeoutError(
                     'Failed to fetch chain. You should not deploy the generated '
                     'certificate, please rerun the command for a new one.')
 
diff --git a/acme/acme/client_test.py b/acme/acme/client_test.py
index 1b33ca5d7..87a04e41c 100644
--- a/acme/acme/client_test.py
+++ b/acme/acme/client_test.py
@@ -8,6 +8,7 @@ from six.moves import http_client  # pylint: disable=import-error
 
 import josepy as jose
 import mock
+import OpenSSL
 import requests
 
 from acme import challenges
@@ -82,6 +83,29 @@ class ClientTestBase(unittest.TestCase):
 class BackwardsCompatibleClientV2Test(ClientTestBase):
     """Tests for  acme.client.BackwardsCompatibleClientV2."""
 
+    def setUp(self):
+        super(BackwardsCompatibleClientV2Test, self).setUp()
+        # contains a loaded cert
+        self.certr = messages.CertificateResource(
+            body=messages_test.CERT)
+
+        loaded = OpenSSL.crypto.load_certificate(
+            OpenSSL.crypto.FILETYPE_PEM, CERT_SAN_PEM)
+        wrapped = jose.ComparableX509(loaded)
+        self.chain = [wrapped, wrapped]
+
+        self.cert_pem = OpenSSL.crypto.dump_certificate(
+            OpenSSL.crypto.FILETYPE_PEM, messages_test.CERT)
+
+        single_chain = OpenSSL.crypto.dump_certificate(
+            OpenSSL.crypto.FILETYPE_PEM, loaded)
+        self.chain_pem = single_chain + single_chain
+
+        self.fullchain_pem = self.cert_pem + self.chain_pem
+
+        self.orderr = messages.OrderResource(
+            csr_pem=CSR_SAN_PEM)
+
     def _init(self):
         uri = 'http://www.letsencrypt-demo.org/directory'
         from acme.client import BackwardsCompatibleClientV2
@@ -182,7 +206,52 @@ class BackwardsCompatibleClientV2Test(ClientTestBase):
             client.new_order(mock_csr_pem)
             mock_client().new_order.assert_called_once_with(mock_csr_pem)
 
+    @mock.patch('acme.client.Client')
+    def test_finalize_order_v1_success(self, mock_client):
+        self.response.json.return_value = DIRECTORY_V1.to_json()
 
+        mock_client().request_issuance.return_value = self.certr
+        mock_client().fetch_chain.return_value = self.chain
+
+        deadline = datetime.datetime(9999, 9, 9)
+        client = self._init()
+        result = client.finalize_order(self.orderr, deadline)
+        self.assertEqual(result.fullchain_pem, self.fullchain_pem)
+        mock_client().fetch_chain.assert_called_once_with(self.certr)
+
+    @mock.patch('acme.client.Client')
+    def test_finalize_order_v1_fetch_chain_error(self, mock_client):
+        self.response.json.return_value = DIRECTORY_V1.to_json()
+
+        mock_client().request_issuance.return_value = self.certr
+        mock_client().fetch_chain.return_value = self.chain
+        mock_client().fetch_chain.side_effect = [errors.Error, mock.DEFAULT]
+
+        deadline = datetime.datetime(9999, 9, 9)
+        client = self._init()
+        result = client.finalize_order(self.orderr, deadline)
+        self.assertEqual(result.fullchain_pem, self.fullchain_pem)
+        self.assertEqual(mock_client().fetch_chain.call_count, 2)
+
+    @mock.patch('acme.client.Client')
+    def test_finalize_order_v1_timeout(self, mock_client):
+        self.response.json.return_value = DIRECTORY_V1.to_json()
+
+        mock_client().request_issuance.return_value = self.certr
+
+        deadline = deadline = datetime.datetime.now() - datetime.timedelta(seconds=60)
+        client = self._init()
+        self.assertRaises(errors.TimeoutError, client.finalize_order,
+            self.orderr, deadline)
+
+    def test_finalize_order_v2(self):
+        self.response.json.return_value = DIRECTORY_V2.to_json()
+        mock_orderr = mock.MagicMock()
+        mock_deadline = mock.MagicMock()
+        with mock.patch('acme.client.ClientV2') as mock_client:
+            client = self._init()
+            client.finalize_order(mock_orderr, mock_deadline)
+            mock_client().finalize_order.assert_called_once_with(mock_orderr, mock_deadline)
 
 
 class ClientTest(ClientTestBase):