diff --git a/samples/snippets/quickstart/sub.py b/samples/snippets/quickstart/sub.py
index 0900f652d..fd99aac2d 100644
--- a/samples/snippets/quickstart/sub.py
+++ b/samples/snippets/quickstart/sub.py
@@ -57,7 +57,7 @@ def callback(message: pubsub_v1.subscriber.message.Message) -> None:
     parser.add_argument("project_id", help="Google Cloud project ID")
     parser.add_argument("subscription_id", help="Pub/Sub subscription ID")
     parser.add_argument(
-        "timeout", default=None, nargs="?", const=1, help="Pub/Sub subscription ID"
+        "timeout", default=None, type=float, nargs="?", const=1, help="StreamingPull timeout in seconds"
     )
 
     args = parser.parse_args()