diff --git a/packages/notebook-extension/src/index.ts b/packages/notebook-extension/src/index.ts
index 928fbc4c41..90c86dcd77 100644
--- a/packages/notebook-extension/src/index.ts
+++ b/packages/notebook-extension/src/index.ts
@@ -14,7 +14,7 @@ import {
 
 import { Cell, CodeCell } from '@jupyterlab/cells';
 
-import { Text, Time } from '@jupyterlab/coreutils';
+import { PageConfig, Text, Time, URLExt } from '@jupyterlab/coreutils';
 
 import { IDocumentManager } from '@jupyterlab/docmanager';
 
@@ -38,9 +38,6 @@ import { Widget } from '@lumino/widgets';
 
 import { TrustedComponent } from './trusted';
 
-import { PageConfig, URLExt } from '@jupyterlab/coreutils';
-
-
 /**
  * The class for kernel status errors.
  */
@@ -415,7 +412,10 @@ const tabIcon: JupyterFrontEndPlugin<void> = {
   activate: (app: JupyterFrontEnd, tracker: INotebookTracker) => {
     // the favicons are provided by Jupyter Server
     const baseURL = PageConfig.getBaseUrl();
-    const notebookIcon = URLExt.join(baseURL, 'static/favicons/favicon-notebook.ico');
+    const notebookIcon = URLExt.join(
+      baseURL,
+      'static/favicons/favicon-notebook.ico'
+    );
     const busyIcon = URLExt.join(baseURL, 'static/favicons/favicon-busy-1.ico');
 
     const updateBrowserFavicon = (