diff --git a/workflows/e2e/action.yaml b/workflows/e2e/action.yaml
index 3df09da..f94e08f 100644
--- a/workflows/e2e/action.yaml
+++ b/workflows/e2e/action.yaml
@@ -26,6 +26,10 @@ inputs:
   scenario:
     description: "The E2E scenario to run"
     required: true
+  ref:
+    description: "The ref to checkout (commit SHA, branch, or tag). Defaults to the repository default branch."
+    required: false
+    default: ""
 outputs:
   result:
     description: "The path to the E2E test results"
@@ -39,6 +43,7 @@ runs:
       uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       with:
         repository: cloudoperators/greenhouse
+        ref: ${{ inputs.ref }}
 
     - name: Set up Go
       uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5