diff --git a/letsencrypt/cli.py b/letsencrypt/cli.py
index 838da4015..c335d8d5b 100644
--- a/letsencrypt/cli.py
+++ b/letsencrypt/cli.py
@@ -856,10 +856,10 @@ def _reconstitute(config, full_path):
     try:
         domains = [le_util.enforce_domain_sanity(x) for x in
                    renewal_candidate.names()]
-    except (UnicodeError, ValueError):
+    except errors.ConfigurationError as error:
         logger.warning("Renewal configuration file %s references a cert "
-                       "that mentions a domain name that we regarded as "
-                       "invalid. Skipping.", full_path)
+                       "that contains an invalid domain name. The problem "
+                       "was: %s. Skipping.", full_path, error)
         return None
 
     setattr(config.namespace, "domains", domains)
diff --git a/letsencrypt/tests/cli_test.py b/letsencrypt/tests/cli_test.py
index aebfd42a6..d0c2f3b91 100644
--- a/letsencrypt/tests/cli_test.py
+++ b/letsencrypt/tests/cli_test.py
@@ -650,7 +650,7 @@ class CLITest(unittest.TestCase):  # pylint: disable=too-many-public-methods
             mock_lineage = mock.MagicMock()
             mock_rc.return_value = mock_lineage
             mock_lineage.configuration = {
-                'renewalparams': {'authenticator': None,
+                'renewalparams': {'authenticator': 'webroot',
                                   'rsa_key_size': 'over 9000'}}
             with mock.patch('letsencrypt.cli.obtain_cert') as mock_obtain_cert:
                 self._test_renewal_common(True, None,
@@ -665,9 +665,9 @@ class CLITest(unittest.TestCase):  # pylint: disable=too-many-public-methods
         with mock.patch('letsencrypt.storage.RenewableCert') as mock_rc:
             mock_lineage = mock.MagicMock()
             mock_rc.return_value = mock_lineage
-            mock_rc.names.return_value = ['*.example.com']
             mock_lineage.configuration = {
-                'renewalparams': {'authenticator': None}}
+                'renewalparams': {'authenticator': 'webroot'}}
+            mock_lineage.names.return_value = ['*.example.com']
             with mock.patch('letsencrypt.cli.obtain_cert') as mock_obtain_cert:
                 self._test_renewal_common(True, None,
                                           args=['renew'], renew=False)