diff --git a/rhodecode/lib/pyramid_utils.py b/rhodecode/lib/pyramid_utils.py
--- a/rhodecode/lib/pyramid_utils.py
+++ b/rhodecode/lib/pyramid_utils.py
@@ -33,7 +33,7 @@ def get_config(ini_path, **kwargs):
 
 def get_app_config(ini_path):
     from paste.deploy.loadwsgi import appconfig
-    return appconfig('config:{}'.format(ini_path), relative_to=os.getcwd())
+    return appconfig(f'config:{ini_path}', relative_to=os.getcwd())
 
 
 def bootstrap(config_uri, options=None, env=None):