diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index 770abe5..badbc95 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -68,6 +68,9 @@ jobs:
       - name: Install saxon
         run: |
           brew install saxon
+      - uses: oven-sh/setup-bun@v2
+        with:
+            bun-version: 1.1.25
       - name: Build with forester
         run: |
           eval $(opam env)