diff --git a/sample/machineset.yaml b/sample/machineset.yaml
index 75759db5b855..899a70896813 100644
--- a/sample/machineset.yaml
+++ b/sample/machineset.yaml
@@ -19,7 +19,6 @@ spec:
           project: "$GCLOUD_PROJECT"
           zone: "us-central1-f"
           machineType: "n1-standard-1"
-          os: "ubuntu-1604-lts"
           image: "projects/ubuntu-os-cloud/global/images/family/ubuntu-1604-lts"
       versions:
         kubelet: 1.9.4