diff --git a/magnum/api/app.py b/magnum/api/app.py
index a54537a42a..aa95f5d540 100644
--- a/magnum/api/app.py
+++ b/magnum/api/app.py
@@ -80,7 +80,7 @@ def load_app():
         cfg_file = cfg_path
 
     if not cfg_file:
-        raise cfg.ConfigFilesNotFoundError([cfg.CONF.api_paste_config])
+        raise cfg.ConfigFilesNotFoundError([cfg.CONF.api.api_paste_config])
     LOG.info(_("Full WSGI config used: %s") % cfg_file)
     return deploy.loadapp("config:" + cfg_file)
 
diff --git a/magnum/tests/unit/api/controllers/test_root.py b/magnum/tests/unit/api/controllers/test_root.py
index c5da1bcac4..727ee4df98 100644
--- a/magnum/tests/unit/api/controllers/test_root.py
+++ b/magnum/tests/unit/api/controllers/test_root.py
@@ -102,6 +102,13 @@ class TestRootController(api_base.FunctionalTest):
         response = self.app.get('/a/bogus/url', expect_errors=True)
         assert response.status_int == 404
 
+    def test_api_paste_file_not_exist(self):
+        cfg.CONF.set_override('api_paste_config', 'non-existent-file',
+                              group='api')
+        with mock.patch.object(cfg.CONF, 'find_file') as ff:
+            ff.return_value = None
+            self.assertRaises(cfg.ConfigFilesNotFoundError, app.load_app)
+
     def test_noauth(self):
         # Don't need to auth
         paste_file = "magnum/tests/unit/api/controllers/noauth-paste.ini"