diff --git a/.github/workflows/AutosarUmlActionExample.yml b/.github/workflows/AutosarUmlActionExample.yml
index c051e48..26f4b91 100644
--- a/.github/workflows/AutosarUmlActionExample.yml
+++ b/.github/workflows/AutosarUmlActionExample.yml
@@ -29,7 +29,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha }}
+          ref: ${{ github.event.pull_request.head.ref }}
           lfs: true
           fetch-depth: 0
       - uses: LieberLieber/setup-LemonTree.Automation@v1