diff --git a/docs/guide/extensions.ipynb b/docs/guide/extensions.ipynb
index 9bd1c56..9a7505c 100644
--- a/docs/guide/extensions.ipynb
+++ b/docs/guide/extensions.ipynb
@@ -800,7 +800,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.1"
+   "version": "3.9.0a6"
   }
  },
  "nbformat": 4,
diff --git a/docs/guide/parsing.ipynb b/docs/guide/parsing.ipynb
index 452f570..fe4df7d 100644
--- a/docs/guide/parsing.ipynb
+++ b/docs/guide/parsing.ipynb
@@ -744,7 +744,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.1"
+   "version": "3.9.0a6"
   }
  },
  "nbformat": 4,
diff --git a/requirements.txt b/requirements.txt
index fa1773a..ed517e0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 bumpversion
 ipython
 nbconvert<6
-nbsphinx==0.4.3
+nbsphinx==0.8.6
 pre-commit
 pygments<3,>=2.4.1
 pytest