diff --git a/.github/workflows/upstream pretest.yaml b/.github/workflows/upstream pretest.yaml
index 518061e8..2b7ccebe 100644
--- a/.github/workflows/upstream pretest.yaml	
+++ b/.github/workflows/upstream pretest.yaml	
@@ -205,7 +205,7 @@ jobs:
                     Push-Location $main_repo_dir
                     $main_repo_url = '${{ github.server_url }}/${{ github.repository }}'
                     Write-Host "fetching commits of: $main_repo_url"
-                    git clone --filter=tree:0 --no-progress $main_repo_url .
+                    git clone --filter=tree:0 --no-progress --no-checkout $main_repo_url .
                     git branch -r
                     
                     $core_removed_pr_nums = @()