diff --git a/.github/workflows/delete-omnistrate-service-plan.yaml b/.github/workflows/delete-omnistrate-service-plan.yaml
index eef4abb..edd6845 100644
--- a/.github/workflows/delete-omnistrate-service-plan.yaml
+++ b/.github/workflows/delete-omnistrate-service-plan.yaml
@@ -14,8 +14,8 @@ jobs:
       max-parallel: 1
       matrix:
         plans:
-          - tier-name: free-${{ github.event_name == 'pull_request' && github.event.pull_request.head.ref || github.ref_name }}
-          - tier-name: pro-${{ github.event_name == 'pull_request' && github.event.pull_request.head.ref || github.ref_name }}
+          - tier-name: free-${{ github.event_name == 'pull_request' && github.base_ref || github.ref_name }}
+          - tier-name: pro-${{ github.event_name == 'pull_request' && github.base_ref || github.ref_name }}
     steps:
 
       - name: Checkout