diff --git a/.github/workflows/write-manifest.yaml b/.github/workflows/write-manifest.yaml
index 4e7ebbd9..b8ea2c0f 100644
--- a/.github/workflows/write-manifest.yaml
+++ b/.github/workflows/write-manifest.yaml
@@ -16,7 +16,7 @@ jobs:
       - name: Checkout repo
         uses: actions/checkout@v3
         with:
-          ref: ${{ github.event.pull_request.head.ref }}
+          fetch-depth: 0
 
       - uses: r-lib/actions/setup-r@v2
         with: