diff --git a/tailbone/app.py b/tailbone/app.py
index 419c9b70..3ccf4ab2 100644
--- a/tailbone/app.py
+++ b/tailbone/app.py
@@ -125,11 +125,15 @@ def make_pyramid_config(settings):
     from tailbone.forms.alchemy import TemplateEngine
     from tailbone.forms import renderers
 
-    config = Configurator(settings=settings, root_factory=Root)
+    config = settings.pop('pyramid_config', None)
+    if config:
+        config.set_root_factory(Root)
+    else:
+        config = Configurator(settings=settings, root_factory=Root)
 
-    # Configure user authentication / authorization.
-    config.set_authentication_policy(SessionAuthenticationPolicy())
+    # configure user authorization / authentication
     config.set_authorization_policy(TailboneAuthorizationPolicy())
+    config.set_authentication_policy(SessionAuthenticationPolicy())
 
     # always require CSRF token protection
     config.set_default_csrf_options(require_csrf=True, token='_csrf')