diff --git a/tests/app/template_sanity_test.py b/tests/app/template_sanity_test.py
index 3a169574f..c46df754d 100644
--- a/tests/app/template_sanity_test.py
+++ b/tests/app/template_sanity_test.py
@@ -15,4 +15,4 @@ async def test_lists_extension(http_server_client, base_url, voila_app):
     response = await http_server_client.fetch(base_url)
     assert response.code == 200
     html_text = response.body.decode('utf-8')
-    assert f'/voila/static/voila.js' in html_text
+    assert '/voila/static/voila.js' in html_text
diff --git a/voila/handler.py b/voila/handler.py
index a7b32a958..26208d0bd 100644
--- a/voila/handler.py
+++ b/voila/handler.py
@@ -17,7 +17,6 @@
 
 from jupyterlab_server.config import get_page_config, recursive_update
 from jupyter_server.base.handlers import JupyterHandler
-from jupyter_server.config_manager import recursive_update
 from jupyter_server.utils import url_path_join
 import nbformat
 
@@ -34,8 +33,6 @@
 
 class PageConfigMixin:
     def get_page_config(self):
-        base_url = self.settings.get("base_url")
-
         page_config = {
             "appVersion": __version__,
             "baseUrl": self.base_url,
@@ -64,7 +61,6 @@ def get_page_config(self):
         return page_config
 
 
-
 class VoilaHandler(JupyterHandler, PageConfigMixin):
 
     def initialize(self, **kwargs):