diff --git a/compute/compute/snippets/sample_start_stop.py b/compute/compute/snippets/sample_start_stop.py
index 1637ee778488..80eb95f8e4e9 100644
--- a/compute/compute/snippets/sample_start_stop.py
+++ b/compute/compute/snippets/sample_start_stop.py
@@ -43,7 +43,7 @@ def start_instance(project_id: str, zone: str, instance_name: str):
     instance_client = compute_v1.InstancesClient()
     op_client = compute_v1.ZoneOperationsClient()
 
-    op = instance_client.start(project=project_id, zone=zone, instance=instance_name)
+    op = instance_client.start_unary(project=project_id, zone=zone, instance=instance_name)
 
     while op.status != compute_v1.Operation.Status.DONE:
         op = op_client.wait(operation=op.name, zone=zone, project=project_id)