--- a/devtools/shared/task.js
+++ b/devtools/shared/task.js
@@ -131,17 +131,17 @@ function isGenerator(value) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 //// Task
 
 /**
  * This object provides the public module functions.
  */
-this.Task = {
+var Task = {
   /**
    * Creates and starts a new task.
    *
    * @param task
    *        - If you specify a generator function, it is called with no
    *          arguments to retrieve the associated iterator.  The generator
    *          function is a task, that is can yield promise objects to wait
    *          upon.