diff --git a/single_app.ipynb b/single_app.ipynb
index 065247d..4d85d7c 100644
--- a/single_app.ipynb
+++ b/single_app.ipynb
@@ -40,8 +40,8 @@
     "url = urlparse.urlsplit(jupyter_notebook_url)  # noqa: F821\n",
     "try:\n",
     "    name = urlparse.parse_qs(url.query)[\"app\"][0]\n",
-    "except KeyError:\n",
-    "    raise ValueError(\"No app specified\")"
+    "except KeyError as e:\n",
+    "    raise ValueError(\"No app specified\") from e"
    ]
   },
   {
diff --git a/tests_notebooks/test_start.py b/tests_notebooks/test_start.py
index 3ff804c..c5ed589 100755
--- a/tests_notebooks/test_start.py
+++ b/tests_notebooks/test_start.py
@@ -20,7 +20,7 @@ def test_click_appstore(selenium_driver, final_screenshot):
     assert len(handles) == 1
     selenium.switch_to.window(handles.pop())
     time.sleep(5)
-    selenium.set_window_size(1200, 941)
+    selenium.set_window_size(1800, 900)
     dropdown = selenium.find_element(
         By.XPATH,
         "//div[@id='notebook-container']/div[5]/div[2]/div[2]/div/div[3]/div/div[2]/div/select",