diff --git a/.github/workflows/deploy-pages.yml b/.github/workflows/deploy-pages.yml
index 53dc653..0202bae 100644
--- a/.github/workflows/deploy-pages.yml
+++ b/.github/workflows/deploy-pages.yml
@@ -35,6 +35,9 @@ jobs:
       - name: Build Sphinx docs
         run: ./build-docs.sh
 
+      - name: Set Binder Python version
+        run: cp runtime.txt docs/build/html/runtime.txt
+
       - name: Publish built docs for Binder
         uses: peaceiris/actions-gh-pages@v4
         with:
diff --git a/runtime.txt b/runtime.txt
new file mode 100644
index 0000000..67ebc4e
--- /dev/null
+++ b/runtime.txt
@@ -0,0 +1 @@
+python-3.11