diff --git a/.github/workflows/sphinx.yml b/.github/workflows/sphinx.yml
index c02715da07..3f24695995 100644
--- a/.github/workflows/sphinx.yml
+++ b/.github/workflows/sphinx.yml
@@ -36,6 +36,7 @@ jobs:
       - uses: actions/checkout@master
         with:
           fetch-depth: 0
+          ref: update-doc
 
       - name: Setup node
         uses: actions/setup-node@v3