diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index f59ecd6c4..7a6c6429a 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -62,7 +62,7 @@ jobs:
       # Popular action to deploy to GitHub Pages:
       # Docs: https://github.com/peaceiris/actions-gh-pages#%EF%B8%8F-docusaurus
       - name: Deploy to GitHub Pages
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@373f7f263a76c20808c831209c920827a82a2847 #v3.9.3
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           # Build output to publish to the `gh-pages` branch: