diff --git a/notebook/app.py b/notebook/app.py
index c06fd7ed50..74a0805b81 100644
--- a/notebook/app.py
+++ b/notebook/app.py
@@ -32,19 +32,18 @@ def get_page_config(self):
         config = LabConfig()
         app = self.extensionapp
         base_url = self.settings.get("base_url")
-        page_config = self.settings.setdefault("page_config_data", {})
-        page_config.update(
-            {
-                "appVersion": version,
-                "baseUrl": self.base_url,
-                "terminalsAvailable": self.settings.get("terminals_available", False),
-                "token": self.settings["token"],
-                "fullStaticUrl": ujoin(self.base_url, "static", self.name),
-                "frontendUrl": ujoin(self.base_url, "/"),
-                "exposeAppInBrowser": app.expose_app_in_browser,
-                "collaborative": app.collaborative,
-            }
-        )
+        page_config_data = self.settings.setdefault("page_config_data", {})
+        page_config = {
+            **page_config_data,
+            "appVersion": version,
+            "baseUrl": self.base_url,
+            "terminalsAvailable": self.settings.get("terminals_available", False),
+            "token": self.settings["token"],
+            "fullStaticUrl": ujoin(self.base_url, "static", self.name),
+            "frontendUrl": ujoin(self.base_url, "/"),
+            "exposeAppInBrowser": app.expose_app_in_browser,
+            "collaborative": app.collaborative,
+        }
 
         if "hub_prefix" in app.serverapp.tornado_settings:
             tornado_settings = app.serverapp.tornado_settings
diff --git a/ui-tests/test/smoke.spec.ts b/ui-tests/test/smoke.spec.ts
index 40cef9a27e..2dedaff397 100644
--- a/ui-tests/test/smoke.spec.ts
+++ b/ui-tests/test/smoke.spec.ts
@@ -73,4 +73,18 @@ test.describe('Smoke', () => {
 
     expect(true).toBe(true);
   });
+
+  test('JupyterLab', async ({ page, tmpPath }) => {
+    // Open the tree page
+    await page.goto(`tree/${tmpPath}`);
+
+    // Open JupyterLab
+    await page.menu.clickMenuItem('View>Open JupyterLab');
+
+    const lab = await page.waitForEvent('popup');
+    await lab.waitForSelector('.jp-Launcher');
+    await lab.close();
+
+    expect(true).toBe(true);
+  });
 });