diff --git a/.github/workflows/book.yml b/.github/workflows/book.yml
index 329eafe..b63b440 100644
--- a/.github/workflows/book.yml
+++ b/.github/workflows/book.yml
@@ -18,7 +18,7 @@ jobs:
       - name: Build
         run: mdbook build
       - name: Deploy
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
         if: ${{ github.ref == 'refs/heads/master' }}
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}