--- a/devtools/client/jsonview/converter-child.js
+++ b/devtools/client/jsonview/converter-child.js
@@ -7,18 +7,16 @@
 "use strict";
 
 const {Cc, Ci, Cu} = require("chrome");
 const { XPCOMUtils } = Cu.import("resource://gre/modules/XPCOMUtils.jsm", {});
 const Services = require("Services");
 
 loader.lazyRequireGetter(this, "NetworkHelper",
                                "devtools/shared/webconsole/network-helper");
-loader.lazyRequireGetter(this, "Events",
-                               "sdk/dom/events");
 loader.lazyRequireGetter(this, "Clipboard",
                                "sdk/clipboard");
 loader.lazyRequireGetter(this, "JsonViewUtils",
                                "devtools/client/jsonview/utils");
 
 const childProcessMessageManager =
   Cc["@mozilla.org/childprocessmessagemanager;1"]
     .getService(Ci.nsISyncMessageSender);
@@ -135,20 +133,20 @@ Converter.prototype = {
           console.error(err);
           return undefined;
         }
       }
     };
 
     JsonViewUtils.exportIntoContentScope(win, Locale, "Locale");
 
-    Events.once(win, "DOMContentLoaded", event => {
+    win.addEventListener("DOMContentLoaded", event => {
       win.addEventListener("contentMessage",
         this.onContentMessage.bind(this), false, true);
-    });
+    }, {once: true});
 
     // The request doesn't have to be always nsIHttpChannel
     // (e.g. in case of data: URLs)
     if (request instanceof Ci.nsIHttpChannel) {
       request.visitResponseHeaders({
         visitHeader: function (name, value) {
           headers.response.push({name: name, value: value});
         }