diff --git a/index.ipynb b/index.ipynb
index f39c97d24dd1ca929feffcd99b5fce5093aab299..2d0110a70a1c82d5077da006878bb6b54adddb1c 100644
--- a/index.ipynb
+++ b/index.ipynb
@@ -470,7 +470,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.4"
+   "version": "3.9.0"
   },
   "toc": {
    "base_numbering": 1,