diff --git a/.eslintrc.es5.json b/.eslintrc.es5.json
index 93521a335e..be8cc36412 100644
--- a/.eslintrc.es5.json
+++ b/.eslintrc.es5.json
@@ -34,7 +34,6 @@
     "no-plusplus": 0,
     "default-case": 0,
     "no-lonely-if": 0,
-    "no-mixed-operators": 0,
     "brace-style": 0,
     "space-infix-ops": 0
   }
diff --git a/assets/js/src/mp2migrator.js b/assets/js/src/mp2migrator.js
index 302d44b64d..cc5be0cc29 100644
--- a/assets/js/src/mp2migrator.js
+++ b/assets/js/src/mp2migrator.js
@@ -61,7 +61,7 @@ define('mp2migrator', ['mailpoet', 'jquery'], function (mp, jQuery) {
         // Move the progress bar
         var progress = 0;
         if ((result.total !== undefined) && (Number(result.total) !== 0)) {
-          progress = Math.round(Number(result.current) / Number(result.total) * 100);
+          progress = Math.round((Number(result.current) / Number(result.total)) * 100);
         }
         jQuery('#progressbar').progressbar('option', 'value', progress);
         jQuery('#progresslabel').html(progress + '%');
diff --git a/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js b/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js
index 052738a9ed..378fcd5d70 100644
--- a/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js
+++ b/assets/js/src/newsletter_editor/behaviors/ContainerDropZoneBehavior.js
@@ -418,7 +418,7 @@ define([
         elementDimension = element.outerWidth(true);
       }
 
-      if (eventOffset <= closeOffset + elementDimension / 2) {
+      if (eventOffset <= closeOffset + (elementDimension / 2)) {
         // First half of the element
         return {
           index: index,
diff --git a/assets/js/src/newsletter_editor/blocks/divider.js b/assets/js/src/newsletter_editor/blocks/divider.js
index 00f5024610..352823708c 100644
--- a/assets/js/src/newsletter_editor/blocks/divider.js
+++ b/assets/js/src/newsletter_editor/blocks/divider.js
@@ -61,7 +61,7 @@ define([
     },
     templateContext: function templateContext() {
       return _.extend({
-        totalHeight: parseInt(this.model.get('styles.block.padding'), 10) * 2 + parseInt(this.model.get('styles.block.borderWidth')) + 'px'
+        totalHeight: (parseInt(this.model.get('styles.block.padding'), 10) * 2) + parseInt(this.model.get('styles.block.borderWidth')) + 'px'
       }, base.BlockView.prototype.templateContext.apply(this));
     },
     onRender: function onRender() {
@@ -75,7 +75,7 @@ define([
     changePadding: function changePadding() {
       this.$('.mailpoet_content').css('padding-top', this.model.get('styles.block.padding'));
       this.$('.mailpoet_content').css('padding-bottom', this.model.get('styles.block.padding'));
-      this.$('.mailpoet_resize_handle_text').text(parseInt(this.model.get('styles.block.padding'), 10) * 2 + parseInt(this.model.get('styles.block.borderWidth')) + 'px');
+      this.$('.mailpoet_resize_handle_text').text((parseInt(this.model.get('styles.block.padding'), 10) * 2) + parseInt(this.model.get('styles.block.borderWidth')) + 'px');
     }
   });
 
diff --git a/assets/js/src/subscribers/importExport/import.js b/assets/js/src/subscribers/importExport/import.js
index 3aa5ac9f8f..f2988790a4 100644
--- a/assets/js/src/subscribers/importExport/import.js
+++ b/assets/js/src/subscribers/importExport/import.js
@@ -246,8 +246,9 @@ define(
                 processedSubscribers = _.values(processedSubscribers);
                 // if the header options is set, there should be at least
                 // 2 data rows, otherwise at least 1 data row
-                if (processedSubscribers &&
-                  (isHeaderFound && processedSubscribers.length >= 2) ||
+                if (
+                  (processedSubscribers && (isHeaderFound && processedSubscribers.length >= 2))
+                  ||
                   (!isHeaderFound && processedSubscribers.length >= 1)
                 ) {
                   // since we assume that the header line is always present, we need