diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3b903d00a9ccb..50d879cc6db37 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -27,7 +27,7 @@ jobs:
       - name: Identify modified files
         id: modified_files
         run: |
-          git fetch origin main
+          git fetch origin {{ github.ref }}
           MODIFIED_FILES=$(git diff --name-only origin/${{ github.ref }} | tr '\n' ',')
           echo "::set-output name=files::$MODIFIED_FILES"