diff --git a/oslo_config/generator.py b/oslo_config/generator.py
index cfdecc83..17977c21 100644
--- a/oslo_config/generator.py
+++ b/oslo_config/generator.py
@@ -257,12 +257,18 @@ def _list_opts(namespaces):
     :param namespaces: a list of namespaces registered under 'oslo.config.opts'
     :returns: a list of (namespace, [(group, [opt_1, opt_2])]) tuples
     """
-    mgr = stevedore.named.NamedExtensionManager('oslo.config.opts',
-                                                names=namespaces,
-                                                invoke_on_load=True)
+    mgr = stevedore.named.NamedExtensionManager(
+        'oslo.config.opts',
+        names=namespaces,
+        on_load_failure_callback=on_load_failure_callback,
+        invoke_on_load=True)
     return [(ep.name, ep.obj) for ep in mgr]
 
 
+def on_load_failure_callback(*args, **kwargs):
+    raise
+
+
 def generate(conf):
     """Generate a sample config file.
 
diff --git a/oslo_config/tests/test_generator.py b/oslo_config/tests/test_generator.py
index 668274c2..5922fb41 100644
--- a/oslo_config/tests/test_generator.py
+++ b/oslo_config/tests/test_generator.py
@@ -525,9 +525,11 @@ class GeneratorTestCase(base.BaseTestCase):
             content = open(output_file).read()
             self.assertEqual(self.expected, content)
 
-        named_mgr.assert_called_once_with('oslo.config.opts',
-                                          names=namespaces,
-                                          invoke_on_load=True)
+        named_mgr.assert_called_once_with(
+            'oslo.config.opts',
+            names=namespaces,
+            on_load_failure_callback=generator.on_load_failure_callback,
+            invoke_on_load=True)
 
         log_warning = getattr(self, 'log_warning', None)
         if log_warning is not None:
@@ -536,4 +538,30 @@ class GeneratorTestCase(base.BaseTestCase):
             self.assertFalse(mock_log.warning.called)
 
 
+class GeneratorRaiseErrorTestCase(base.BaseTestCase):
+
+    def test_generator_raises_error(self):
+        """Verifies that errors from extension manager are not suppressed."""
+        class FakeException(Exception):
+            pass
+
+        class FakeEP(object):
+
+            def __init__(self):
+                self.name = 'callback_is_expected'
+                self.require = self.resolve
+                self.load = self.resolve
+
+            def resolve(self, *args, **kwargs):
+                raise FakeException()
+
+        fake_ep = FakeEP()
+        self.conf = cfg.ConfigOpts()
+        self.conf.register_opts(generator._generator_opts)
+        self.conf.set_default('namespace', fake_ep.name)
+        fake_eps = mock.Mock(return_value=[fake_ep])
+        with mock.patch('pkg_resources.iter_entry_points', fake_eps):
+            self.assertRaises(FakeException, generator.generate, self.conf)
+
+
 GeneratorTestCase.generate_scenarios()
diff --git a/tests/test_generator.py b/tests/test_generator.py
index e4768672..6717da08 100644
--- a/tests/test_generator.py
+++ b/tests/test_generator.py
@@ -540,9 +540,11 @@ class GeneratorTestCase(base.BaseTestCase):
             content = open(output_file).read()
             self.assertEqual(self.expected, content)
 
-        named_mgr.assert_called_once_with('oslo.config.opts',
-                                          names=namespaces,
-                                          invoke_on_load=True)
+        named_mgr.assert_called_once_with(
+            'oslo.config.opts',
+            names=namespaces,
+            on_load_failure_callback=generator.on_load_failure_callback,
+            invoke_on_load=True)
 
         log_warning = getattr(self, 'log_warning', None)
         if log_warning is not None: