diff --git a/docs/source/demo_type_annotation.ipynb b/docs/source/demo_type_annotation.ipynb
index e4138698f64b84b3bddd93e1ff2313c3d16741a9..51ba38ff5833283061802ebe91d376c67492b0af 100644
--- a/docs/source/demo_type_annotation.ipynb
+++ b/docs/source/demo_type_annotation.ipynb
@@ -72,21 +72,12 @@
    "execution_count": 3,
    "id": "3b323abd-7689-4abd-aa02-049b1de7bfcb",
    "metadata": {},
-   "outputs": [
-    {
-     "ename": "NameError",
-     "evalue": "name 'Optional' is not defined",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mNameError\u001b[0m                                 Traceback (most recent call last)",
-      "Cell \u001b[0;32mIn[3], line 1\u001b[0m\n\u001b[0;32m----> 1\u001b[0m x0: Optional[\u001b[38;5;28mint\u001b[39m] \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mNone\u001b[39;00m\n",
-      "\u001b[0;31mNameError\u001b[0m: name 'Optional' is not defined"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
-    "fx0: Optional[int] = None"
+    "from typing import Optional, Union\n",
+    "\n",
+    "x_optional: Optional[int] = None\n",
+    "x_union: Union[float, int] = 1.23"
    ]
   },
   {
@@ -102,7 +93,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 4,
    "id": "d93f8b14-5f88-4579-a671-1693d04ce144",
    "metadata": {},
    "outputs": [],
@@ -114,7 +105,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 5,
    "id": "14b83562-b6c6-4873-8936-ad9d0c9c0e6f",
    "metadata": {},
    "outputs": [],