diff --git a/aiidalab_widgets_base/static/styles/test.css b/tests_notebooks/static/styles/test.css
similarity index 100%
rename from aiidalab_widgets_base/static/styles/test.css
rename to tests_notebooks/static/styles/test.css
diff --git a/tests_notebooks/test_notebook.ipynb b/tests_notebooks/test_notebook.ipynb
index 861c98604..edffd72d5 100644
--- a/tests_notebooks/test_notebook.ipynb
+++ b/tests_notebooks/test_notebook.ipynb
@@ -26,10 +26,9 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# DO NOT REMOVE!\n",
-    "# This triggers required jupyter-notebook specific actions.\n",
-    "# See `aiidalab_widgets_base.__init__.py` for details\n",
-    "import aiidalab_widgets_base"
+    "from aiidalab_widgets_base.utils.loaders import load_css\n",
+    "\n",
+    "load_css(css_path=\"static/styles/test.css\")"
    ]
   },
   {