diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
index 2b4c202..0a2ce74 100644
--- a/.github/workflows/backport.yml
+++ b/.github/workflows/backport.yml
@@ -73,9 +73,12 @@ jobs:
       issues: write
       pull-requests: write
     steps:
-      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+      - name: Check out trusted base branch
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           fetch-depth: 0
+          repository: ${{ github.event.pull_request.base.repo.full_name }}
+          ref: refs/heads/${{ github.event.pull_request.base.ref }}
       - name: Create backport PRs
         uses: korthout/backport-action@66065406958f46e82238fd59546f5a99e69e22aa # v4.5.2
         with: