diff --git a/dev/update_packages.dart b/dev/update_packages.dart
old mode 100644
new mode 100755
index 4c97507a02..c72350bf59
--- a/dev/update_packages.dart
+++ b/dev/update_packages.dart
@@ -1,3 +1,4 @@
+#!/usr/bin/env dart
 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.