diff --git a/extensions/firefox/content/PdfJsTelemetry-stub.jsm b/extensions/firefox/content/PdfJsTelemetry-stub.jsm
index 047941dfe..69f4a1844 100644
--- a/extensions/firefox/content/PdfJsTelemetry-stub.jsm
+++ b/extensions/firefox/content/PdfJsTelemetry-stub.jsm
@@ -15,9 +15,9 @@
 
 "use strict";
 
-this.EXPORTED_SYMBOLS = ["PdfJsTelemetry"];
+var EXPORTED_SYMBOLS = ["PdfJsTelemetry"];
 
-this.PdfJsTelemetry = {
+var PdfJsTelemetry = {
   onViewerIsUsed() {
   },
   onFallback() {
diff --git a/extensions/firefox/content/PdfJsTelemetry.jsm b/extensions/firefox/content/PdfJsTelemetry.jsm
index 4fc6efe76..0436debd2 100644
--- a/extensions/firefox/content/PdfJsTelemetry.jsm
+++ b/extensions/firefox/content/PdfJsTelemetry.jsm
@@ -16,11 +16,11 @@
 
 "use strict";
 
-this.EXPORTED_SYMBOLS = ["PdfJsTelemetry"];
+var EXPORTED_SYMBOLS = ["PdfJsTelemetry"];
 
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 
-this.PdfJsTelemetry = {
+var PdfJsTelemetry = {
   onViewerIsUsed() {
     let histogram = Services.telemetry.getHistogramById("PDF_VIEWER_USED");
     histogram.add(true);
diff --git a/extensions/firefox/content/PdfStreamConverter.jsm b/extensions/firefox/content/PdfStreamConverter.jsm
index a546dfb9c..613553c48 100644
--- a/extensions/firefox/content/PdfStreamConverter.jsm
+++ b/extensions/firefox/content/PdfStreamConverter.jsm
@@ -41,6 +41,8 @@ ChromeUtils.defineModuleGetter(this, "PdfJsTelemetry",
 ChromeUtils.defineModuleGetter(this, "PdfjsContentUtils",
   "resource://pdf.js/PdfjsContentUtils.jsm");
 
+Cu.importGlobalProperties(["XMLHttpRequest"]);
+
 var Svc = {};
 XPCOMUtils.defineLazyServiceGetter(Svc, "mime",
                                    "@mozilla.org/mime;1",
@@ -593,8 +595,6 @@ class RangedChromeActions extends ChromeActions {
       }
     };
     var getXhr = function getXhr() {
-      const XMLHttpRequest = Components.Constructor(
-          "@mozilla.org/xmlextras/xmlhttprequest;1");
       var xhr = new XMLHttpRequest();
       xhr.addEventListener("readystatechange", xhr_onreadystatechange);
       return xhr;
diff --git a/package.json b/package.json
index 9705fe184..828ecc707 100644
--- a/package.json
+++ b/package.json
@@ -9,9 +9,9 @@
     "babel-preset-env": "^1.6.1",
     "core-js": "^2.5.3",
     "escodegen": "^1.9.0",
-    "eslint": "^4.17.0",
-    "eslint-plugin-mozilla": "^0.8.1",
-    "eslint-plugin-no-unsanitized": "^2.0.2",
+    "eslint": "^4.18.1",
+    "eslint-plugin-mozilla": "^0.9.0",
+    "eslint-plugin-no-unsanitized": "^3.0.0",
     "fancy-log": "^1.3.2",
     "gulp": "^3.9.1",
     "gulp-rename": "^1.2.2",