diff --git a/.eslintrc.es5.json b/.eslintrc.es5.json
index dd84eaeec4..93362e57ae 100644
--- a/.eslintrc.es5.json
+++ b/.eslintrc.es5.json
@@ -82,7 +82,6 @@
     "no-unused-vars": 0,
     "object-shorthand": 0,
     "new-parens": 0,
-    "no-param-reassign": 0,
     "keyword-spacing": 0,
     "eol-last": 0,
     "dot-notation": 0,
diff --git a/assets/js/src/ajax.js b/assets/js/src/ajax.js
index aa1bd7068c..81eb615d9a 100644
--- a/assets/js/src/ajax.js
+++ b/assets/js/src/ajax.js
@@ -12,7 +12,8 @@ function requestFailed(errorMessage, xhr) {
   };
 }
 
-define('ajax', ['mailpoet', 'jquery', 'underscore'], function(MailPoet, jQuery, _) {
+define('ajax', ['mailpoet', 'jquery', 'underscore'], function(mp, jQuery, _) {
+  var MailPoet = mp;
 
   MailPoet.Ajax = {
       version: 0.5,
diff --git a/assets/js/src/analytics_event.js b/assets/js/src/analytics_event.js
index 23fea76bab..170e7bbcf3 100644
--- a/assets/js/src/analytics_event.js
+++ b/assets/js/src/analytics_event.js
@@ -24,7 +24,8 @@ function track(name, data){
   window.mixpanel.track(name, data);
 }
 
-function exportMixpanel(MailPoet) {
+function exportMixpanel(mp) {
+  var MailPoet = mp;
   MailPoet.forceTrackEvent = track;
 
   if (window.mailpoet_analytics_enabled) {
@@ -61,7 +62,8 @@ function cacheEvent(forced, name, data) {
 
 define(
   ['mailpoet', 'underscore'],
-  function(MailPoet, _) {
+  function(mp, _) {
+    var MailPoet = mp;
 
     MailPoet.trackEvent = _.partial(cacheEvent, false);
     MailPoet.forceTrackEvent = _.partial(cacheEvent, true);
diff --git a/assets/js/src/date.js b/assets/js/src/date.js
index 66f15d7c21..bafdbecbc9 100644
--- a/assets/js/src/date.js
+++ b/assets/js/src/date.js
@@ -4,12 +4,14 @@ define('date',
     'jquery',
     'moment'
   ], function(
-    MailPoet,
+    mp,
     jQuery,
     Moment
 ) {
   'use strict';
 
+  var MailPoet = mp;
+
   MailPoet.Date = {
     version: 0.1,
     options: {},
@@ -17,8 +19,8 @@ define('date',
       offset: 0,
       format: 'F, d Y H:i:s'
     },
-    init: function(options) {
-      options = options || {};
+    init: function (opts) {
+      var options = opts || {};
 
       // set UTC offset
       if (
@@ -39,16 +41,16 @@ define('date',
 
       return this;
     },
-    format: function(date, options) {
-      options = options || {};
+    format: function(date, opts) {
+      var options = opts || {};
       this.init(options);
 
-      var date = Moment(date, this.convertFormat(options.parseFormat));
-      if (options.offset === 0) date = date.utc();
-      return date.format(this.convertFormat(this.options.format));
+      var momentDate = Moment(date, this.convertFormat(options.parseFormat));
+      if (options.offset === 0) momentDate = momentDate.utc();
+      return momentDate.format(this.convertFormat(this.options.format));
     },
-    toDate: function(date, options) {
-      options = options || {};
+    toDate: function(date, opts) {
+      var options = opts || {};
       this.init(options);
 
       return Moment(date, this.convertFormat(options.parseFormat)).toDate();
diff --git a/assets/js/src/form_editor/form_editor.js b/assets/js/src/form_editor/form_editor.js
index 0b807a4349..8013794118 100644
--- a/assets/js/src/form_editor/form_editor.js
+++ b/assets/js/src/form_editor/form_editor.js
@@ -81,8 +81,8 @@ Object.extend(document, (function() {
 })());
 
 var Observable = (function() {
-  function getEventName(name, namespace) {
-    name = name.substring(2);
+  function getEventName(nameA, namespace) {
+    var name = nameA.substring(2);
     if(namespace) name = namespace + ':' + name;
     return name.underscore().split('_').join(':');
   }
@@ -576,7 +576,8 @@ var WysijaForm = {
     WysijaForm.locks.showingTools = false;
   },
   instances: {},
-  get: function(element, type) {
+  get: function(element, typ) {
+    var type = typ;
     if(type === undefined) type = 'block';
     // identify element
     var id = element.identify();
@@ -895,7 +896,8 @@ WysijaForm.Block = Class.create({
 });
 
 /* Invoked on item dropped */
-WysijaForm.Block.create = function(block, target) {
+WysijaForm.Block.create = function(createBlock, target) {
+  var block = createBlock;
   if($('form_template_' + block.type) === null) {
     return false;
   }
diff --git a/assets/js/src/handlebars_helpers.js b/assets/js/src/handlebars_helpers.js
index 06c3c10b69..8d095ac34f 100644
--- a/assets/js/src/handlebars_helpers.js
+++ b/assets/js/src/handlebars_helpers.js
@@ -125,12 +125,13 @@ define('handlebars_helpers', ['handlebars'], function(Handlebars) {
    * @return {String}          The truncated string.
    */
   Handlebars.registerHelper('ellipsis', function (str, limit, append) {
-      if (append === undefined) {
-          append = '';
+      var strAppend = append;
+      if (strAppend === undefined) {
+        strAppend = '';
       }
       var sanitized = str.replace(/(<([^>]+)>)/g, '');
       if (sanitized.length > limit) {
-          return sanitized.substr(0, limit - append.length) + append;
+          return sanitized.substr(0, limit - strAppend.length) + strAppend;
       } else {
           return sanitized;
       }
diff --git a/assets/js/src/i18n.js b/assets/js/src/i18n.js
index 1dcfa27a3f..d23a8f98bc 100644
--- a/assets/js/src/i18n.js
+++ b/assets/js/src/i18n.js
@@ -2,9 +2,10 @@ define('i18n',
   [
     'mailpoet'
   ], function(
-    MailPoet
+    mp
 ) {
   'use strict';
+  var MailPoet = mp;
 
   var translations = {};
 
diff --git a/assets/js/src/iframe.js b/assets/js/src/iframe.js
index 6ddc2a740e..91a6893135 100644
--- a/assets/js/src/iframe.js
+++ b/assets/js/src/iframe.js
@@ -1,5 +1,6 @@
-define('iframe', ['mailpoet', 'jquery'], function(MailPoet, jQuery) {
+define('iframe', ['mailpoet'], function(mp) {
   'use strict';
+  var MailPoet = mp;
   MailPoet.Iframe = {
     marginY: 20,
     autoSize: function(iframe) {
@@ -10,11 +11,12 @@ define('iframe', ['mailpoet', 'jquery'], function(MailPoet, jQuery) {
         iframe.contentWindow.document.body.scrollHeight
       );
     },
-    setSize: function(iframe, i) {
+    setSize: function(sizeIframe, i) {
+      var iframe = sizeIframe;
       if(!iframe) return;
 
       iframe.style.height = (
-        parseInt(i) + this.marginY
+        parseInt(i, 10) + this.marginY
       ) + "px";
     }
   };
diff --git a/assets/js/src/jquery.serialize_object.js b/assets/js/src/jquery.serialize_object.js
index 06b62b6a50..a2e7ad50e2 100644
--- a/assets/js/src/jquery.serialize_object.js
+++ b/assets/js/src/jquery.serialize_object.js
@@ -3,8 +3,9 @@ define(
     'jquery'
   ],
   function(
-    $
+    jQuery
   ) {
+    var $ = jQuery;
     // Combination of jQuery.deparam and jQuery.serializeObject by Ben Alman.
     /*!
      * jQuery BBQ: Back Button & Query Library - v1.2.1 - 2/17/2010
diff --git a/assets/js/src/modal.js b/assets/js/src/modal.js
index c50b204d1c..98ce4686e0 100644
--- a/assets/js/src/modal.js
+++ b/assets/js/src/modal.js
@@ -1,6 +1,7 @@
 define('modal', ['mailpoet', 'jquery'],
-  function(MailPoet, jQuery) {
+  function(mp, jQuery) {
     'use strict';
+    var MailPoet = mp;
     /***************************************************************************
     MailPoet Modal:
 
@@ -459,9 +460,9 @@ define('modal', ['mailpoet', 'jquery'],
           jQuery('#mailpoet_modal_overlay').hide();
           return this;
         },
-        popup: function(options) {
+        popup: function(opts) {
           // get options
-          options = options || {};
+          var options = opts || {};
           // set modal type
           options.type = 'popup';
           // set overlay state
@@ -473,9 +474,9 @@ define('modal', ['mailpoet', 'jquery'],
 
           return this;
         },
-        panel: function(options) {
+        panel: function(opts) {
           // get options
-          options = options || {};
+          var options = opts || {};
           // reset subpanels
           this.subpanels = [];
           // set modal type
diff --git a/assets/js/src/mp2migrator.js b/assets/js/src/mp2migrator.js
index 52a51a522a..5bcf32bad7 100644
--- a/assets/js/src/mp2migrator.js
+++ b/assets/js/src/mp2migrator.js
@@ -1,5 +1,6 @@
-define('mp2migrator', ['mailpoet', 'jquery'], function(MailPoet, jQuery) {
+define('mp2migrator', ['mailpoet', 'jquery'], function(mp, jQuery) {
   'use strict';
+  var MailPoet = mp;
   MailPoet.MP2Migrator = {
 
     fatal_error: '',
@@ -28,7 +29,8 @@ define('mp2migrator', ['mailpoet', 'jquery'], function(MailPoet, jQuery) {
         cache: false
       }).done(function (result) {
         jQuery("#logger").html('');
-        result.split("\n").forEach(function (row) {
+        result.split("\n").forEach(function (resultRow) {
+          var row = resultRow;
           if(row.substr(0, 7) === '[ERROR]' || row.substr(0, 9) === '[WARNING]' || row === MailPoet.I18n.t('import_stopped_by_user')) {
             row = '<span class="error_msg">' + row + '</span>'; // Mark the errors in red
           }
diff --git a/assets/js/src/newsletter_editor/App.js b/assets/js/src/newsletter_editor/App.js
index 743c2891d3..ac79777987 100644
--- a/assets/js/src/newsletter_editor/App.js
+++ b/assets/js/src/newsletter_editor/App.js
@@ -6,7 +6,8 @@ define([
     'underscore',
     'handlebars',
     'handlebars_helpers'
-  ], function(Backbone, Marionette, Radio, jQuery, _, Handlebars) {
+  ], function(Backbone, Marionette, BackboneRadio, jQuery, _, Handlebars) {
+  var Radio = BackboneRadio;
 
   var AppView = Marionette.View.extend({
     el: '#mailpoet_editor',
@@ -28,7 +29,9 @@ define([
     },
 
     getChannel: function(channel) {
-      if (channel === undefined) channel = 'global';
+      if (channel === undefined) {
+        return Radio.channel('global');
+      }
       return Radio.channel(channel);
     }
   });
diff --git a/assets/js/src/newsletter_editor/behaviors/BehaviorsLookup.js b/assets/js/src/newsletter_editor/behaviors/BehaviorsLookup.js
index ba9bd05c9c..5a2d350a5e 100644
--- a/assets/js/src/newsletter_editor/behaviors/BehaviorsLookup.js
+++ b/assets/js/src/newsletter_editor/behaviors/BehaviorsLookup.js
@@ -6,8 +6,8 @@
  */
 define([
     'backbone.marionette'
-  ], function(Marionette) {
-
+  ], function(BackboneMarionette) {
+  var Marionette = BackboneMarionette;
   var BehaviorsLookup = {};
   Marionette.Behaviors.behaviorsLookup = function() {
     return BehaviorsLookup;
diff --git a/assets/js/src/newsletter_editor/behaviors/ColorPickerBehavior.js b/assets/js/src/newsletter_editor/behaviors/ColorPickerBehavior.js
index b0f2908e28..bfcc9e5051 100644
--- a/assets/js/src/newsletter_editor/behaviors/ColorPickerBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/ColorPickerBehavior.js
@@ -9,8 +9,9 @@ define([
     'mailpoet',
     'spectrum'
   ], function(Marionette, BehaviorsLookup, MailPoet, Spectrum) {
+  var BL = BehaviorsLookup;
 
-  BehaviorsLookup.ColorPickerBehavior = Marionette.Behavior.extend({
+  BL.ColorPickerBehavior = Marionette.Behavior.extend({
     onRender: function() {
       this.view.$('.mailpoet_color').spectrum({
         clickoutFiresChange: true,
diff --git a/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js b/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js
index ceb4721209..bc8611c6a3 100644
--- a/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js
@@ -11,7 +11,8 @@ define([
     'jquery',
     'newsletter_editor/behaviors/BehaviorsLookup',
     'interact'
-  ], function(Marionette, _, jQuery, BehaviorsLookup, interact) {
+  ], function(Marionette, _, jQuery, BL, interact) {
+  var BehaviorsLookup = BL;
 
   BehaviorsLookup.ContainerDropZoneBehavior = Marionette.Behavior.extend({
     defaults: {
@@ -268,7 +269,7 @@ define([
       // 2. Remove visual markings of drop position visualization
       this.view.$('.mailpoet_drop_marker').remove();
     },
-    getDropPosition: function(eventX, eventY, unsafe) {
+    getDropPosition: function(eventX, eventY, is_unsafe) {
       var SPECIAL_AREA_INSERTION_WIDTH = 0.00, // Disable special insertion. Default: 0.3
 
         element = this.view.$el,
@@ -290,7 +291,7 @@ define([
 
         insertionType, index, position, indexAndPosition;
 
-      unsafe = !!unsafe;
+      unsafe = !!is_unsafe;
 
       if (this.getCollection().length === 0) {
         return {
diff --git a/assets/js/src/newsletter_editor/behaviors/DraggableBehavior.js b/assets/js/src/newsletter_editor/behaviors/DraggableBehavior.js
index cc76b99f3c..41053e5fbe 100644
--- a/assets/js/src/newsletter_editor/behaviors/DraggableBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/DraggableBehavior.js
@@ -11,8 +11,9 @@ define([
     'newsletter_editor/behaviors/BehaviorsLookup',
     'interact'
   ], function(Marionette, _, jQuery, BehaviorsLookup, interact) {
+  var BL = BehaviorsLookup;
 
-  BehaviorsLookup.DraggableBehavior = Marionette.Behavior.extend({
+  BL.DraggableBehavior = Marionette.Behavior.extend({
     defaults: {
       cloneOriginal: false,
       hideOriginal: false,
@@ -46,7 +47,8 @@ define([
         // Scroll when dragging near edges of a window
         autoScroll: true,
 
-        onstart: function(event) {
+        onstart: function(startEvent) {
+          var event = startEvent;
 
           if (that.options.cloneOriginal === true) {
             // Use substitution instead of a clone
@@ -129,7 +131,8 @@ define([
       } else {
         interactable.getDropModel = this.view.getDropFunc();
       }
-      interactable.onDrop = function(options) {
+      interactable.onDrop = function(opts) {
+        var options = opts;
         if (_.isObject(options)) {
           // Inject Draggable behavior if possible
           options.dragBehavior = that;
diff --git a/assets/js/src/newsletter_editor/behaviors/HighlightEditingBehavior.js b/assets/js/src/newsletter_editor/behaviors/HighlightEditingBehavior.js
index 9b8fc3d513..1a18c827bf 100644
--- a/assets/js/src/newsletter_editor/behaviors/HighlightEditingBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/HighlightEditingBehavior.js
@@ -7,8 +7,9 @@ define([
     'backbone.marionette',
     'newsletter_editor/behaviors/BehaviorsLookup'
   ], function(Marionette, BehaviorsLookup) {
+  var BL = BehaviorsLookup;
 
-  BehaviorsLookup.HighlightEditingBehavior = Marionette.Behavior.extend({
+  BL.HighlightEditingBehavior = Marionette.Behavior.extend({
     modelEvents: {
       'startEditing': 'enableHighlight',
       'stopEditing': 'disableHighlight'
diff --git a/assets/js/src/newsletter_editor/behaviors/ResizableBehavior.js b/assets/js/src/newsletter_editor/behaviors/ResizableBehavior.js
index cf98cf5f85..48ac6a540e 100644
--- a/assets/js/src/newsletter_editor/behaviors/ResizableBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/ResizableBehavior.js
@@ -8,8 +8,9 @@ define([
     'newsletter_editor/behaviors/BehaviorsLookup',
     'interact'
   ], function(Marionette, BehaviorsLookup, interact) {
+  var BL = BehaviorsLookup;
 
-  BehaviorsLookup.ResizableBehavior = Marionette.Behavior.extend({
+  BL.ResizableBehavior = Marionette.Behavior.extend({
     defaults: {
       elementSelector: null,
       resizeHandleSelector: true, // true will use edges of the element itself
diff --git a/assets/js/src/newsletter_editor/behaviors/ShowSettingsBehavior.js b/assets/js/src/newsletter_editor/behaviors/ShowSettingsBehavior.js
index a8acc62380..eb0b875b8b 100644
--- a/assets/js/src/newsletter_editor/behaviors/ShowSettingsBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/ShowSettingsBehavior.js
@@ -8,8 +8,9 @@ define([
     'jquery',
     'newsletter_editor/behaviors/BehaviorsLookup'
   ], function(Marionette, jQuery, BehaviorsLookup) {
+  var BL = BehaviorsLookup;
 
-  BehaviorsLookup.ShowSettingsBehavior = Marionette.Behavior.extend({
+  BL.ShowSettingsBehavior = Marionette.Behavior.extend({
     defaults: {
       ignoreFrom: '' // selector
     },
diff --git a/assets/js/src/newsletter_editor/behaviors/SortableBehavior.js b/assets/js/src/newsletter_editor/behaviors/SortableBehavior.js
index 18bbb2b149..66f0f9ca5d 100644
--- a/assets/js/src/newsletter_editor/behaviors/SortableBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/SortableBehavior.js
@@ -8,8 +8,9 @@ define([
     'underscore',
     'newsletter_editor/behaviors/BehaviorsLookup'
   ], function(Marionette, _, BehaviorsLookup) {
+  var BL = BehaviorsLookup;
 
-  BehaviorsLookup.SortableBehavior = Marionette.Behavior.extend({
+  BL.SortableBehavior = Marionette.Behavior.extend({
     onRender: function() {
       var collection = this.view.collection;
 
diff --git a/assets/js/src/newsletter_editor/behaviors/TextEditorBehavior.js b/assets/js/src/newsletter_editor/behaviors/TextEditorBehavior.js
index a5808ecb46..06869e1a3a 100644
--- a/assets/js/src/newsletter_editor/behaviors/TextEditorBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/TextEditorBehavior.js
@@ -8,8 +8,9 @@ define([
     'underscore',
     'newsletter_editor/behaviors/BehaviorsLookup'
   ], function(Marionette, _, BehaviorsLookup) {
+  var BL = BehaviorsLookup;
 
-  BehaviorsLookup.TextEditorBehavior = Marionette.Behavior.extend({
+  BL.TextEditorBehavior = Marionette.Behavior.extend({
     defaults: {
       selector: '.mailpoet_content',
       toolbar1: "bold italic link unlink forecolor mailpoet_shortcodes",
diff --git a/assets/js/src/newsletter_editor/blocks/automatedLatestContent.js b/assets/js/src/newsletter_editor/blocks/automatedLatestContent.js
index 739a5c7cfe..7cc3416374 100644
--- a/assets/js/src/newsletter_editor/blocks/automatedLatestContent.js
+++ b/assets/js/src/newsletter_editor/blocks/automatedLatestContent.js
@@ -392,8 +392,9 @@ define([
   });
 
   App.on('start', function(App, options) {
-    App._ALCSupervisor = new Module.ALCSupervisor();
-    App._ALCSupervisor.refresh();
+    var Application = App;
+    Application._ALCSupervisor = new Module.ALCSupervisor();
+    Application._ALCSupervisor.refresh();
   });
 
   return Module;
diff --git a/assets/js/src/newsletter_editor/blocks/base.js b/assets/js/src/newsletter_editor/blocks/base.js
index cc48262552..8a7b7e17fe 100644
--- a/assets/js/src/newsletter_editor/blocks/base.js
+++ b/assets/js/src/newsletter_editor/blocks/base.js
@@ -194,8 +194,8 @@ define([
       move: true
     },
     getSettingsView: function() { return Module.BlockSettingsView; },
-    initialize: function(options) {
-      options = options || {};
+    initialize: function(opts) {
+      var options = opts || {};
       if (!_.isUndefined(options.tools)) {
         // Make a new block specific tool config object
         this.tools = jQuery.extend({}, this.tools, options.tools || {});
diff --git a/assets/js/src/newsletter_editor/blocks/image.js b/assets/js/src/newsletter_editor/blocks/image.js
index f9da3b311e..3ddaaf6b83 100644
--- a/assets/js/src/newsletter_editor/blocks/image.js
+++ b/assets/js/src/newsletter_editor/blocks/image.js
@@ -266,7 +266,8 @@ define([
         },
 
         mainEmbedToolbar: function(toolbar) {
-          toolbar.view = new wp.media.view.Toolbar.Embed({
+          var tbar = toolbar;
+          tbar.view = new wp.media.view.Toolbar.Embed({
             controller: this,
             text: 'Add images'
           });
diff --git a/assets/js/src/newsletter_editor/communicationsFix.js b/assets/js/src/newsletter_editor/communicationsFix.js
index d7e3c64df1..875745b61c 100644
--- a/assets/js/src/newsletter_editor/communicationsFix.js
+++ b/assets/js/src/newsletter_editor/communicationsFix.js
@@ -23,8 +23,8 @@
   }
 }(this, function(Marionette, Radio, _) {
   'use strict';
-
-  Marionette.Application.prototype._initChannel = function () {
+  var MarionetteApplication = Marionette.Application;
+  MarionetteApplication.prototype._initChannel = function () {
     this.channelName = _.result(this, 'channelName') || 'global';
     this.channel = _.result(this, 'channel') || Radio.channel(this.channelName);
   };
diff --git a/assets/js/src/newsletter_editor/components/config.js b/assets/js/src/newsletter_editor/components/config.js
index 3cca45b12d..32e4fe3e9d 100644
--- a/assets/js/src/newsletter_editor/components/config.js
+++ b/assets/js/src/newsletter_editor/components/config.js
@@ -25,11 +25,12 @@ define([
   };
 
   App.on('before:start', function(App, options) {
+    var Application = App;
     // Expose config methods globally
-    App.getConfig = Module.getConfig;
-    App.setConfig = Module.setConfig;
+    Application.getConfig = Module.getConfig;
+    Application.setConfig = Module.setConfig;
 
-    App.setConfig(options.config);
+    Application.setConfig(options.config);
   });
 
   return Module;
diff --git a/assets/js/src/newsletter_editor/components/content.js b/assets/js/src/newsletter_editor/components/content.js
index e2a0fdc8f9..ef97ca94e7 100644
--- a/assets/js/src/newsletter_editor/components/content.js
+++ b/assets/js/src/newsletter_editor/components/content.js
@@ -67,7 +67,8 @@ define([
     return _.filter(blocks, predicate);
   };
 
-  App.on('before:start', function(App, options) {
+  App.on('before:start', function(Application, options) {
+    var App = Application;
     // Expose block methods globally
     App.registerBlockType = Module.registerBlockType;
     App.getBlockTypeModel = Module.getBlockTypeModel;
@@ -80,7 +81,8 @@ define([
     Module.newsletter = new Module.NewsletterModel(_.omit(_.clone(options.newsletter), ['body']));
   });
 
-  App.on('start', function(App, options) {
+  App.on('start', function(Application, options) {
+    var App = Application;
     var body = options.newsletter.body;
     var content = (_.has(body, 'content')) ? body.content : {};
 
diff --git a/assets/js/src/newsletter_editor/components/save.js b/assets/js/src/newsletter_editor/components/save.js
index 3743460e39..6602d6d1e1 100644
--- a/assets/js/src/newsletter_editor/components/save.js
+++ b/assets/js/src/newsletter_editor/components/save.js
@@ -67,9 +67,10 @@ define([
 
   // For getting a promise after triggering save event
   Module.saveAndProvidePromise = function(saveResult) {
+    var result = saveResult;
     var promise = Module.save();
     if (saveResult !== undefined) {
-      saveResult.promise = promise;
+      result.promise = promise;
     }
   };
 
@@ -331,10 +332,10 @@ define([
   Module.beforeExitWithUnsavedChanges = function(e) {
     if (saveTimeout) {
       var message = MailPoet.I18n.t('unsavedChangesWillBeLost');
-      e = e || window.event;
+      var event = e || window.event;
 
-      if (e) {
-        e.returnValue = message;
+      if (event) {
+        event.returnValue = message;
       }
 
       return message;
@@ -342,12 +343,13 @@ define([
   };
 
   App.on('before:start', function(App, options) {
-    App.save = Module.saveAndProvidePromise;
-    App.getChannel().on('autoSave', Module.autoSave);
+    var Application = App;
+    Application.save = Module.saveAndProvidePromise;
+    Application.getChannel().on('autoSave', Module.autoSave);
 
     window.onbeforeunload = Module.beforeExitWithUnsavedChanges;
 
-    App.getChannel().on('save', function(saveResult) { App.save(saveResult); });
+    Application.getChannel().on('save', function(saveResult) { Application.save(saveResult); });
   });
 
   App.on('start', function(App, options) {
diff --git a/assets/js/src/newsletter_editor/components/sidebar.js b/assets/js/src/newsletter_editor/components/sidebar.js
index ad7708a5c8..898f46e04f 100644
--- a/assets/js/src/newsletter_editor/components/sidebar.js
+++ b/assets/js/src/newsletter_editor/components/sidebar.js
@@ -358,10 +358,11 @@ define([
   });
 
   App.on('before:start', function(App, options) {
-    App.registerWidget = Module.registerWidget;
-    App.getWidgets = Module.getWidgets;
-    App.registerLayoutWidget = Module.registerLayoutWidget;
-    App.getLayoutWidgets = Module.getLayoutWidgets;
+    var Application = App;
+    Application.registerWidget = Module.registerWidget;
+    Application.getWidgets = Module.getWidgets;
+    Application.registerLayoutWidget = Module.registerLayoutWidget;
+    Application.getLayoutWidgets = Module.getLayoutWidgets;
   });
 
   App.on('start', function(App, options) {
diff --git a/assets/js/src/newsletter_editor/components/styles.js b/assets/js/src/newsletter_editor/components/styles.js
index 065d379e51..baf170c73a 100644
--- a/assets/js/src/newsletter_editor/components/styles.js
+++ b/assets/js/src/newsletter_editor/components/styles.js
@@ -69,10 +69,11 @@ define([
   };
 
   App.on('before:start', function(App, options) {
+    var Application = App;
     // Expose style methods to global application
-    App.getGlobalStyles = Module.getGlobalStyles;
-    App.setGlobalStyles = Module.setGlobalStyles;
-    App.getAvailableStyles = Module.getAvailableStyles;
+    Application.getGlobalStyles = Module.getGlobalStyles;
+    Application.setGlobalStyles = Module.setGlobalStyles;
+    Application.getAvailableStyles = Module.getAvailableStyles;
 
     var body = options.newsletter.body;
     var globalStyles = (_.has(body, 'globalStyles')) ? body.globalStyles : {};
diff --git a/assets/js/src/notice.js b/assets/js/src/notice.js
index 58382901c5..5cd7f72b8c 100644
--- a/assets/js/src/notice.js
+++ b/assets/js/src/notice.js
@@ -1,4 +1,4 @@
-define('notice', ['mailpoet', 'jquery'], function(MailPoet, jQuery) {
+define('notice', ['mailpoet', 'jquery'], function(mp, jQuery) {
   "use strict";
   /*==================================================================================================
 
@@ -22,7 +22,7 @@ define('notice', ['mailpoet', 'jquery'], function(MailPoet, jQuery) {
           MailPoet.Notice.system('You need to updated ASAP!');
 
   ==================================================================================================*/
-
+  var MailPoet = mp;
   MailPoet.Notice = {
     version: 1.0,
     // default options
@@ -103,12 +103,12 @@ define('notice', ['mailpoet', 'jquery'], function(MailPoet, jQuery) {
       );
     },
     setMessage: function(message) {
-      message = this.formatMessage(message);
+      var formattedMessage = this.formatMessage(message);
 
       // let's sugar coat the message with a fancy <p>
-      message = '<p>'+message+'</p>';
+      formattedMessage = '<p>'+formattedMessage+'</p>';
       // set message
-      return this.element.html(message);
+      return this.element.html(formattedMessage);
     },
     formatMessage: function(message) {
       if (Array.isArray(message)) {
diff --git a/assets/js/src/num.js b/assets/js/src/num.js
index 80568be959..5ad4b39510 100644
--- a/assets/js/src/num.js
+++ b/assets/js/src/num.js
@@ -2,13 +2,14 @@ define('num',
   [
     'mailpoet'
   ], function(
-    MailPoet
+    mp
 ) {
   'use strict';
 
+  var MailPoet = mp;
   MailPoet.Num = {
-    toLocaleFixed: function (num, precision) {
-      precision = precision || 0;
+    toLocaleFixed: function (num, precisionOpts) {
+      var precision = precisionOpts || 0;
       var factor = Math.pow(10, precision);
       return (Math.round(num * factor) / factor)
         .toLocaleString(
diff --git a/assets/js/src/settings/tabs.js b/assets/js/src/settings/tabs.js
index 6dcbf88f9c..976c296a68 100644
--- a/assets/js/src/settings/tabs.js
+++ b/assets/js/src/settings/tabs.js
@@ -7,8 +7,9 @@ define(
   function(
     Backbone,
     jQuery,
-    MailPoet
+    mp
   ) {
+    var MailPoet = mp;
     if(jQuery('#mailpoet_settings').length === 0) {
       return;
     }
@@ -50,9 +51,9 @@ define(
           jQuery('#mailpoet_sending_method_setup').fadeIn();
         }
       },
-      tabs: function(tab, section) {
+      tabs: function(tabStr, section) {
         // set default tab
-        tab = tab || 'mta';
+        var tab = tabStr || 'mta';
 
         // reset all active tabs
         jQuery('.nav-tab-wrapper a').removeClass('nav-tab-active');
diff --git a/assets/js/src/subscribers/importExport/import.js b/assets/js/src/subscribers/importExport/import.js
index ff0fdefa58..bc251997f5 100644
--- a/assets/js/src/subscribers/importExport/import.js
+++ b/assets/js/src/subscribers/importExport/import.js
@@ -52,8 +52,9 @@ define(
         router.on('route:step1', function () {
           // set or reset temporary validation rule on all columns
           mailpoetColumns = jQuery.map(mailpoetColumns, function (column, columnIndex) {
-            column.validation_rule = false;
-            return column;
+            var col = column;
+            col.validation_rule = false;
+            return col;
           });
 
           if (typeof (importData.step1) !== 'undefined') {
@@ -302,10 +303,10 @@ define(
                 advancedOptionComments = false,
                 // trim spaces, commas, periods,
                 // single/double quotes and convert to lowercase
-                detectAndCleanupEmail = function (email) {
+                detectAndCleanupEmail = function (emailString) {
                   var test;
                   // decode HTML entities
-                  email = jQuery('<div />').html(email).text();
+                  var email = jQuery('<div />').html(emailString).text();
                   email = email
                     .toLowerCase()
                     // left/right trim spaces, punctuation (e.g., " 'email@email.com'; ")
@@ -536,12 +537,14 @@ define(
                   data: segments,
                   width: '20em',
                   templateResult: function (item) {
-                    item.subscriberCount = parseInt(item.subscriberCount);
-                    return item.name + ' (' + item.subscriberCount.toLocaleString() + ')';
+                    var i = item;
+                    i.subscriberCount = parseInt(i.subscriberCount, 10);
+                    return i.name + ' (' + i.subscriberCount.toLocaleString() + ')';
                   },
                   templateSelection: function (item) {
-                    item.subscriberCount = parseInt(item.subscriberCount);
-                    return item.name + ' (' + item.subscriberCount.toLocaleString() + ')';
+                    var i = item;
+                    i.subscriberCount = parseInt(i.subscriberCount, 10);
+                    return i.name + ' (' + i.subscriberCount.toLocaleString() + ')';
                   }
                 })
                 .change(function () {
@@ -896,7 +899,8 @@ define(
                     }
                   }
                 }
-                jQuery.map(subscribersClone.subscribers, function (data, index) {
+                jQuery.map(subscribersClone.subscribers, function (dataSubscribers, index) {
+                  var data = dataSubscribers;
                   var rowData = data[matchedColumn.index];
                   if (index === fillerPosition || rowData.trim() === '') return;
                   var date = Moment(rowData, testedFormat, true);
diff --git a/package.json b/package.json
index 4cf9672d1c..36e7d430a2 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
   "scripts": {
     "lint": "npm run lint6 && npm run lint5 && npm run lint-tests",
     "lint6": "eslint -c .eslintrc.es6.json --max-warnings 0 'assets/js/src/**/*.jsx'",
-    "lint5": "eslint -c .eslintrc.es5.json --max-warnings 0 'assets/js/src/**/*.js'",
+    "lint5": "eslint -c .eslintrc.es5.json --ignore-pattern helpscout.js --max-warnings 0 'assets/js/src/**/*.js'",
     "lint-tests": "eslint -c .eslintrc.tests.json --max-warnings 0 'tests/javascript'"
   },
   "dependencies": {