diff --git a/browser/.eslintrc.js b/browser/.eslintrc.js
index 6f0bffef89c9..f794a69567c5 100644
--- a/browser/.eslintrc.js
+++ b/browser/.eslintrc.js
@@ -7,6 +7,6 @@ module.exports = {
 
   "rules": {
     "no-shadow": "error",
-    "no-undef": "error"
+    "no-undef": "off"
   }
 };
diff --git a/browser/base/.eslintrc.js b/browser/base/.eslintrc.js
index d4b366151b97..978d7b372998 100644
--- a/browser/base/.eslintrc.js
+++ b/browser/base/.eslintrc.js
@@ -1,7 +1,4 @@
 "use strict";
 
 module.exports = {
-  rules: {
-    "no-undef": "off"
-  }
 };
diff --git a/browser/components/.eslintrc.js b/browser/components/.eslintrc.js
deleted file mode 100644
index d4b366151b97..000000000000
--- a/browser/components/.eslintrc.js
+++ /dev/null
@@ -1,7 +0,0 @@
-"use strict";
-
-module.exports = {
-  rules: {
-    "no-undef": "off"
-  }
-};
diff --git a/browser/extensions/pocket/content/main.js b/browser/extensions/pocket/content/main.js
index d07e6d2992b2..25e7c54f36b6 100644
--- a/browser/extensions/pocket/content/main.js
+++ b/browser/extensions/pocket/content/main.js
@@ -42,7 +42,6 @@
 // TODO : [nice to have] - Immediately save, buffer the actions in a local queue and send (so it works offline, works like our native extensions)
 
 /* eslint-disable no-shadow */
-/* eslint "mozilla/import-browserjs-globals": "error" */
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils",
diff --git a/browser/extensions/presentation/bootstrap.js b/browser/extensions/presentation/bootstrap.js
index 68a7f5bd4b35..d81e3643adaa 100644
--- a/browser/extensions/presentation/bootstrap.js
+++ b/browser/extensions/presentation/bootstrap.js
@@ -58,8 +58,7 @@ var Presentation = {
   init() {
     log("init");
     // Register PresentationDevicePrompt into a XPCOM component.
-    let {PresentationDevicePrompt} = Cu.import(PRESENTATION_DEVICE_PROMPT_PATH, {});
-    this.PresentationDevicePrompt = PresentationDevicePrompt;
+    Cu.import(PRESENTATION_DEVICE_PROMPT_PATH);
     this._register();
   },
 
@@ -67,7 +66,6 @@ var Presentation = {
     log("uninit");
     // Unregister PresentationDevicePrompt XPCOM component.
     this._unregister();
-    delete this.PresentationDevicePrompt;
     Cu.unload(PRESENTATION_DEVICE_PROMPT_PATH);
   },
 
@@ -75,7 +73,7 @@ var Presentation = {
   _register() {
     log("_register");
     this._devicePromptFactory = new Factory();
-    this._devicePromptFactory.register(this.PresentationDevicePrompt);
+    this._devicePromptFactory.register(PresentationDevicePrompt);
   },
 
   _unregister() {
diff --git a/browser/extensions/shield-recipe-client/lib/CleanupManager.jsm b/browser/extensions/shield-recipe-client/lib/CleanupManager.jsm
index a25ee45ec17f..2e5f2867f374 100644
--- a/browser/extensions/shield-recipe-client/lib/CleanupManager.jsm
+++ b/browser/extensions/shield-recipe-client/lib/CleanupManager.jsm
@@ -4,8 +4,6 @@
 
 "use strict";
 
-const {utils: Cu} = Components;
-
 this.EXPORTED_SYMBOLS = ["CleanupManager"];
 
 const cleanupHandlers = new Set();
diff --git a/browser/extensions/webcompat-reporter/bootstrap.js b/browser/extensions/webcompat-reporter/bootstrap.js
index e7015b67ccba..51006c8d451f 100644
--- a/browser/extensions/webcompat-reporter/bootstrap.js
+++ b/browser/extensions/webcompat-reporter/bootstrap.js
@@ -2,8 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/* global APP_SHUTDOWN:false */
-
 let { classes: Cc, interfaces: Ci, utils: Cu } = Components;
 
 Cu.import("resource://gre/modules/Services.jsm");
diff --git a/browser/extensions/webcompat-reporter/content/WebCompatReporter.jsm b/browser/extensions/webcompat-reporter/content/WebCompatReporter.jsm
index d722267a87ea..ce68fdd191ae 100644
--- a/browser/extensions/webcompat-reporter/content/WebCompatReporter.jsm
+++ b/browser/extensions/webcompat-reporter/content/WebCompatReporter.jsm
@@ -31,8 +31,7 @@ let WebCompatReporter = {
   },
 
   init() {
-    let TabListener = Cu.import(TABLISTENER_JSM, {});
-    this.TabListener = TabListener;
+    Cu.import(TABLISTENER_JSM);
 
     let styleSheetService = Cc["@mozilla.org/content/style-sheet-service;1"]
       .getService(Ci.nsIStyleSheetService);
@@ -62,7 +61,7 @@ let WebCompatReporter = {
       .getInterface(Ci.nsIDOMWindowUtils)
       .addSheet(this._cachedSheet, this._sheetType);
     // Attach listeners to new window.
-    win._webcompatReporterTabListener = new this.TabListener(win);
+    win._webcompatReporterTabListener = new TabListener(win);
   },
 
   onWindowClosed(win) {
@@ -84,7 +83,6 @@ let WebCompatReporter = {
     }
 
     CustomizableUI.removeListener(this);
-    delete this.TabListener;
     Cu.unload(TABLISTENER_JSM);
   },
 
diff --git a/browser/extensions/webcompat-reporter/content/tab-frame.js b/browser/extensions/webcompat-reporter/content/tab-frame.js
index f94ddfc4f72d..3ec978775eb6 100644
--- a/browser/extensions/webcompat-reporter/content/tab-frame.js
+++ b/browser/extensions/webcompat-reporter/content/tab-frame.js
@@ -2,8 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/* global content:false, sendAsyncMessage:false */
-
 let { utils: Cu } = Components;
 
 const TABDATA_MESSAGE = "WebCompat:SendTabData";
diff --git a/browser/extensions/webcompat-reporter/content/wc-frame.js b/browser/extensions/webcompat-reporter/content/wc-frame.js
index c1c047b53804..f37f344d5780 100644
--- a/browser/extensions/webcompat-reporter/content/wc-frame.js
+++ b/browser/extensions/webcompat-reporter/content/wc-frame.js
@@ -2,8 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/* global content:false, addMessageListener:false, removeMessageListener: false */
-
 let { utils: Cu } = Components;
 
 const SCREENSHOT_MESSAGE = "WebCompat:SendScreenshot";
diff --git a/browser/extensions/webcompat/test/.eslintrc.js b/browser/extensions/webcompat/test/.eslintrc.js
deleted file mode 100644
index c764b133dc9c..000000000000
--- a/browser/extensions/webcompat/test/.eslintrc.js
+++ /dev/null
@@ -1,7 +0,0 @@
-"use strict";
-
-module.exports = {
-  "extends": [
-    "../../../../testing/mochitest/browser.eslintrc.js"
-  ]
-};
diff --git a/browser/modules/test/browser_NetworkPrioritizer.js b/browser/modules/test/browser_NetworkPrioritizer.js
index c88e06545f62..a70961561aee 100644
--- a/browser/modules/test/browser_NetworkPrioritizer.js
+++ b/browser/modules/test/browser_NetworkPrioritizer.js
@@ -19,12 +19,11 @@ function* getPriority(aBrowser) {
     aBrowser = aBrowser.linkedBrowser;
 
   return yield ContentTask.spawn(aBrowser, null, function* () {
-    return content.document.docShell
-      .QueryInterface(Components.interfaces.nsIWebNavigation)
-      .QueryInterface(Components.interfaces.nsIDocumentLoader)
-      .loadGroup
-      .QueryInterface(Components.interfaces.nsISupportsPriority)
-      .priority;
+    return docShell.QueryInterface(Components.interfaces.nsIWebNavigation)
+                   .QueryInterface(Components.interfaces.nsIDocumentLoader)
+                   .loadGroup
+                   .QueryInterface(Components.interfaces.nsISupportsPriority)
+                   .priority;
   });
 }
 
@@ -33,12 +32,11 @@ function* setPriority(aBrowser, aPriority) {
     aBrowser = aBrowser.linkedBrowser;
 
   yield ContentTask.spawn(aBrowser, aPriority, function* (contentPriority) {
-    content.document.docShell
-      .QueryInterface(Components.interfaces.nsIWebNavigation)
-      .QueryInterface(Components.interfaces.nsIDocumentLoader)
-      .loadGroup
-      .QueryInterface(Ci.nsISupportsPriority)
-      .priority = contentPriority;
+    docShell.QueryInterface(Components.interfaces.nsIWebNavigation)
+                                    .QueryInterface(Components.interfaces.nsIDocumentLoader)
+                                    .loadGroup
+                                    .QueryInterface(Ci.nsISupportsPriority)
+                                    .priority = contentPriority;
   });
 }
 
diff --git a/browser/modules/test/contentSearch.js b/browser/modules/test/contentSearch.js
index 9bf641647f1e..1dd5d846dfed 100644
--- a/browser/modules/test/contentSearch.js
+++ b/browser/modules/test/contentSearch.js
@@ -2,8 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/* global addMessageListener:false, sendAsyncMessage:false, XPCOMUtils */
-
 const TEST_MSG = "ContentSearchTest";
 const SERVICE_EVENT_TYPE = "ContentSearchService";
 const CLIENT_EVENT_TYPE = "ContentSearchClient";
@@ -40,8 +38,8 @@ addMessageListener(TEST_MSG, msg => {
 
 function waitForLoadAndStopIt(expectedURL, callback) {
   let Ci = Components.interfaces;
-  let webProgress = content.document.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
-                                             .getInterface(Ci.nsIWebProgress);
+  let webProgress = docShell.QueryInterface(Ci.nsIInterfaceRequestor)
+                            .getInterface(Ci.nsIWebProgress);
   let listener = {
     onStateChange(webProg, req, flags, status) {
       if (req instanceof Ci.nsIChannel) {
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browserjs-globals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browserjs-globals.js
index ff6c1362dbbb..4650e92b1f7d 100644
--- a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browserjs-globals.js
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browserjs-globals.js
@@ -54,16 +54,13 @@ const SCRIPTS = [
 module.exports = function(context) {
   return {
     Program: function(node) {
-      let filepath = helpers.getAbsoluteFilePath(context);
-      let root = helpers.getRootDir(filepath);
-      let relativepath = path.relative(root, filepath);
-
-      if ((helpers.getTestType(this) != "browser" &&
-          !helpers.getIsHeadFile(this)) &&
-          !relativepath.includes("content")) {
+      if (helpers.getTestType(this) != "browser" &&
+          !helpers.getIsHeadFile(this)) {
         return;
       }
 
+      let filepath = helpers.getAbsoluteFilePath(context);
+      let root = helpers.getRootDir(filepath);
       for (let script of SCRIPTS) {
         let fileName = path.join(root, script);
         try {
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/package.json b/tools/lint/eslint/eslint-plugin-mozilla/package.json
index 42cd7c37e60c..92df733fab58 100644
--- a/tools/lint/eslint/eslint-plugin-mozilla/package.json
+++ b/tools/lint/eslint/eslint-plugin-mozilla/package.json
@@ -1,6 +1,6 @@
 {
   "name": "eslint-plugin-mozilla",
-  "version": "0.2.18",
+  "version": "0.2.17",
   "description": "A collection of rules that help enforce JavaScript coding standard in the Mozilla project.",
   "keywords": [
     "eslint",