diff --git a/.github/workflows/book.yml b/.github/workflows/book.yml
index 45e5e203..8ef0a274 100644
--- a/.github/workflows/book.yml
+++ b/.github/workflows/book.yml
@@ -25,6 +25,16 @@ jobs:
           with:
             working-directory: .github/hello-world
 
+    sphinx:
+      runs-on: "ubuntu-latest"
+      steps:
+        - name: Checkout [${{ github.repository }}]
+          uses: actions/checkout@v4
+
+        - uses: ./actions/uv/sphinx
+          with:
+            working-directory: .github/hello-world
+
     test:
       runs-on: "ubuntu-latest"
       steps:
@@ -47,7 +57,7 @@ jobs:
 
     book:
       runs-on: "ubuntu-latest"
-      needs: [test, pdoc, jupyter, marimo]
+      needs: [test, pdoc, sphinx, jupyter, marimo]
 
       permissions:
         contents: write