diff --git a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/interfaces.py b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/interfaces.py
index fde1f2d45..b0785fa8e 100644
--- a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/interfaces.py
+++ b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/interfaces.py
@@ -8,6 +8,12 @@ import letsencrypt.interfaces
 
 class IPluginProxy(zope.interface.Interface):
     """Wraps a Let's Encrypt plugin"""
+    http_port = zope.interface.Attribute(
+        "The port to connect to on localhost for HTTP traffic")
+
+    https_port = zope.interface.Attribute(
+        "The port to connect to on localhost for HTTPS traffic")
+
     def add_parser_arguments(cls, parser):
         """Adds command line arguments needed by the parser"""
 
@@ -27,26 +33,15 @@ class IPluginProxy(zope.interface.Interface):
     def load_config():
         """Loads the next config and returns its name"""
 
-
-class IConfiguratorBaseProxy(IPluginProxy):
-    """Common functionality for authenticator/installer tests"""
-    http_port = zope.interface.Attribute(
-        "The port to connect to on localhost for HTTP traffic")
-
-    https_port = zope.interface.Attribute(
-        "The port to connect to on localhost for HTTPS traffic")
-
     def get_testable_domain_names():
         """Returns the domain names that can be used in testing"""
 
 
-class IAuthenticatorProxy(
-        IConfiguratorBaseProxy, letsencrypt.interfaces.IAuthenticator):
+class IAuthenticatorProxy(IPluginProxy, letsencrypt.interfaces.IAuthenticator):
     """Wraps a Let's Encrypt authenticator"""
 
 
-class IInstallerProxy(
-        IConfiguratorBaseProxy, letsencrypt.interfaces.IInstaller):
+class IInstallerProxy(IPluginProxy, letsencrypt.interfaces.IInstaller):
     """Wraps a Let's Encrypt installer"""
 
     def get_all_names_answer():
diff --git a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/test_driver.py b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/test_driver.py
index e50335b4a..9ac8c43ae 100644
--- a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/test_driver.py
+++ b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/test_driver.py
@@ -41,8 +41,9 @@ def test_authenticator(plugin, config, temp_dir):
 
     achalls = _create_achalls(plugin)
     if not achalls:
-        # Plugin/tests support no common challenge types
-        return True
+        logger.error("The plugin and this program support no common "
+                     "challenge types")
+        return False
 
     try:
         responses = plugin.perform(achalls)
@@ -208,7 +209,7 @@ def _save_and_restart(plugin, title=None):
 def test_rollback(plugin, config, backup):
     """Tests the rollback checkpoints function"""
     try:
-        plugin.rollback_checkpoints(2)
+        plugin.rollback_checkpoints(1337)
     except le_errors.Error as error:
         logger.error("Plugin raised an exception during rollback:")
         logger.exception(error)
@@ -281,7 +282,7 @@ def setup_logging(args):
     handler = logging.StreamHandler()
 
     root_logger = logging.getLogger()
-    root_logger.setLevel(logging.WARNING - args.verbose_count * 10)
+    root_logger.setLevel(logging.ERROR - args.verbose_count * 10)
     root_logger.addHandler(handler)