diff --git a/.github/workflows/assign-reviewers.yml b/.github/workflows/assign-reviewers.yml
index 3a34dd151170..1e9e5dd7f167 100644
--- a/.github/workflows/assign-reviewers.yml
+++ b/.github/workflows/assign-reviewers.yml
@@ -16,6 +16,7 @@ jobs:
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
         with:
+          ref: ${{ github.event.pull_request.base.ref }}
           persist-credentials: false
       - name: Set up Python
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405  # v6.2.0