diff --git a/.github/workflows/pr-author-check.yml b/.github/workflows/pr-author-check.yml
index cc0b204a..2e43b4aa 100644
--- a/.github/workflows/pr-author-check.yml
+++ b/.github/workflows/pr-author-check.yml
@@ -16,4 +16,6 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GITHUB_EVENT_PATH: ${{ github.event_path }}
         run: |
+          git fetch origin ${{ github.base_ref }} --depth 1
+          git fetch origin ${{ github.head_ref }} --depth 1
           sh -x .github/workflows/check_authors.sh "origin/${{ github.base_ref }}..origin/${{ github.head_ref }}"
\ No newline at end of file