diff --git a/.eslintrc.es6.json b/.eslintrc.es6.json
index 7e8dd0750c..fd70eb060d 100644
--- a/.eslintrc.es6.json
+++ b/.eslintrc.es6.json
@@ -40,7 +40,6 @@
     "jsx-a11y/alt-text": 0,
     "func-names": 0,
     "object-shorthand": 0,
-    "arrow-body-style": 0,
     "prefer-template": 0,
     "default-case": 0,
     "array-callback-return": 0,
diff --git a/assets/js/src/form/fields/checkbox.jsx b/assets/js/src/form/fields/checkbox.jsx
index a4c2a047f6..5303eed810 100644
--- a/assets/js/src/form/fields/checkbox.jsx
+++ b/assets/js/src/form/fields/checkbox.jsx
@@ -18,23 +18,21 @@ define([
       // it will be false in case value is "0" or empty
       const isChecked = !!(Number(this.props.item[this.props.field.name]));
       const options = Object.keys(this.props.field.values).map(
-        (value, index) => {
-          return (
-            <p key={'checkbox-' + index}>
-              <label>
-                <input
-                  ref="checkbox"
-                  type="checkbox"
-                  value="1"
-                  checked={isChecked}
-                  onChange={this.onValueChange}
-                  name={this.props.field.name}
+        (value, index) => (
+          <p key={'checkbox-' + index}>
+            <label>
+              <input
+                ref="checkbox"
+                type="checkbox"
+                value="1"
+                checked={isChecked}
+                onChange={this.onValueChange}
+                name={this.props.field.name}
                 />
-                { this.props.field.values[value] }
-              </label>
-            </p>
-          );
-        }
+              { this.props.field.values[value] }
+            </label>
+          </p>
+          )
       );
 
       return (
diff --git a/assets/js/src/form/fields/field.jsx b/assets/js/src/form/fields/field.jsx
index 1495677050..d681ec4117 100644
--- a/assets/js/src/form/fields/field.jsx
+++ b/assets/js/src/form/fields/field.jsx
@@ -89,14 +89,12 @@ define([
       let field = false;
 
       if (this.props.field.fields !== undefined) {
-        field = this.props.field.fields.map((subfield, index) => {
-          return this.renderField({
-            index: index,
-            field: subfield,
-            item: this.props.item,
-            onValueChange: this.props.onValueChange || false,
-          });
-        });
+        field = this.props.field.fields.map((subfield, index) => this.renderField({
+          index: index,
+          field: subfield,
+          item: this.props.item,
+          onValueChange: this.props.onValueChange || false,
+        }));
       } else {
         field = this.renderField(this.props);
       }
diff --git a/assets/js/src/form/fields/radio.jsx b/assets/js/src/form/fields/radio.jsx
index 4d13160b8d..9c6ae03a20 100644
--- a/assets/js/src/form/fields/radio.jsx
+++ b/assets/js/src/form/fields/radio.jsx
@@ -12,21 +12,19 @@ define([
 
       const selected_value = this.props.item[this.props.field.name];
       const options = Object.keys(this.props.field.values).map(
-        (value, index) => {
-          return (
-            <p key={'radio-' + index}>
-              <label>
-                <input
-                  type="radio"
-                  checked={selected_value === value}
-                  value={value}
-                  onChange={this.props.onValueChange}
-                  name={this.props.field.name} />
-                { this.props.field.values[value] }
-              </label>
-            </p>
-          );
-        }
+        (value, index) => (
+          <p key={'radio-' + index}>
+            <label>
+              <input
+                type="radio"
+                checked={selected_value === value}
+                value={value}
+                onChange={this.props.onValueChange}
+                name={this.props.field.name} />
+              { this.props.field.values[value] }
+            </label>
+          </p>
+          )
       );
 
       return (
diff --git a/assets/js/src/form/fields/selection.jsx b/assets/js/src/form/fields/selection.jsx
index 0ca27b1ff6..9bba5a2522 100644
--- a/assets/js/src/form/fields/selection.jsx
+++ b/assets/js/src/form/fields/selection.jsx
@@ -88,9 +88,7 @@ define([
       } else if (this.props.item !== undefined && this.props.field.name !== undefined) {
         if (this.allowMultipleValues()) {
           if (Array.isArray(this.props.item[this.props.field.name])) {
-            return this.props.item[this.props.field.name].map((item) => {
-              return item.id;
-            });
+            return this.props.item[this.props.field.name].map(item => item.id);
           }
         } else {
           return this.props.item[this.props.field.name];
diff --git a/assets/js/src/form/form.jsx b/assets/js/src/form/form.jsx
index 1cf4fc72f4..9a175dca30 100644
--- a/assets/js/src/form/form.jsx
+++ b/assets/js/src/form/form.jsx
@@ -155,13 +155,11 @@ define(
       render: function () {
         let errors;
         if (this.getErrors() !== undefined) {
-          errors = this.getErrors().map((error, index) => {
-            return (
-              <p key={'error-' + index} className="mailpoet_error">
-                { error.message }
-              </p>
-            );
-          });
+          errors = this.getErrors().map((error, index) => (
+            <p key={'error-' + index} className="mailpoet_error">
+              { error.message }
+            </p>
+            ));
         }
 
         const formClasses = classNames(
diff --git a/assets/js/src/forms/list.jsx b/assets/js/src/forms/list.jsx
index cef1eb35db..35ce257101 100644
--- a/assets/js/src/forms/list.jsx
+++ b/assets/js/src/forms/list.jsx
@@ -110,7 +110,7 @@ const item_actions = [
       }).fail((response) => {
         if (response.errors.length > 0) {
           MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
         }
@@ -133,7 +133,7 @@ const FormList = React.createClass({
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
@@ -146,11 +146,7 @@ const FormList = React.createClass({
       'has-row-actions'
     );
 
-    let segments = window.mailpoet_segments.filter((segment) => {
-      return (jQuery.inArray(segment.id, form.segments) !== -1);
-    }).map((segment) => {
-      return segment.name;
-    }).join(', ');
+    let segments = window.mailpoet_segments.filter(segment => (jQuery.inArray(segment.id, form.segments) !== -1)).map(segment => segment.name).join(', ');
 
     if (form.settings.segments_selected_by === 'user') {
       segments = MailPoet.I18n.t('userChoice') + ' ' + segments;
diff --git a/assets/js/src/help/system_info.jsx b/assets/js/src/help/system_info.jsx
index 2ebaf6faec..fc2ecd9aff 100644
--- a/assets/js/src/help/system_info.jsx
+++ b/assets/js/src/help/system_info.jsx
@@ -9,9 +9,7 @@ function handleFocus(event) {
 
 function printData(data) {
   if (_.isObject(data)) {
-    const printableData = Object.keys(data).map((key) => {
-      return `${key}: ${data[key]}`;
-    });
+    const printableData = Object.keys(data).map(key => `${key}: ${data[key]}`);
 
     return (<textarea
       readOnly={true}
diff --git a/assets/js/src/listing/bulk_actions.jsx b/assets/js/src/listing/bulk_actions.jsx
index 70ba92e429..af0fd1fec7 100644
--- a/assets/js/src/listing/bulk_actions.jsx
+++ b/assets/js/src/listing/bulk_actions.jsx
@@ -67,9 +67,7 @@ define([
     getSelectedAction: function () {
       const selected_action = this.refs.action.value;
       if (selected_action.length > 0) {
-        const action = this.props.bulk_actions.filter((act) => {
-          return (act.name === selected_action);
-        });
+        const action = this.props.bulk_actions.filter(act => (act.name === selected_action));
 
         if (action.length > 0) {
           return action[0];
@@ -97,14 +95,12 @@ define([
             onChange={this.handleChangeAction}
           >
             <option value="">{MailPoet.I18n.t('bulkActions')}</option>
-            { this.props.bulk_actions.map((action, index) => {
-              return (
-                <option
-                  value={action.name}
-                  key={'action-' + index}
+            { this.props.bulk_actions.map((action, index) => (
+              <option
+                value={action.name}
+                key={'action-' + index}
                 >{ action.label }</option>
-              );
-            }) }
+              )) }
           </select>
           <input
             onClick={this.handleApplyAction}
diff --git a/assets/js/src/listing/filters.jsx b/assets/js/src/listing/filters.jsx
index d24fb7b9e0..641fe4a543 100644
--- a/assets/js/src/listing/filters.jsx
+++ b/assets/js/src/listing/filters.jsx
@@ -24,15 +24,13 @@ define([
     },
     getAvailableFilters: function () {
       const filters = this.props.filters;
-      return Object.keys(filters).filter((filter) => {
-        return !(
+      return Object.keys(filters).filter(filter => !(
           filters[filter].length === 0
           || (
             filters[filter].length === 1
             && !filters[filter][0].value
           )
-        );
-      });
+        ));
     },
     componentDidUpdate: function () {
       const selected_filters = this.props.filter;
@@ -49,24 +47,20 @@ define([
     render: function () {
       const filters = this.props.filters;
       const available_filters = this.getAvailableFilters()
-        .map((filter, i) => {
-          return (
-            <select
-              ref={`filter-${i}`}
-              key={`filter-${i}`}
-              name={filter}
+        .map((filter, i) => (
+          <select
+            ref={`filter-${i}`}
+            key={`filter-${i}`}
+            name={filter}
             >
-              { filters[filter].map((option, j) => {
-                return (
-                  <option
-                    value={option.value}
-                    key={'filter-option-' + j}
+            { filters[filter].map((option, j) => (
+              <option
+                value={option.value}
+                key={'filter-option-' + j}
                 >{ option.label }</option>
-                );
-              }) }
-            </select>
-          );
-        });
+                )) }
+          </select>
+          ));
 
       let button;
 
diff --git a/assets/js/src/listing/listing.jsx b/assets/js/src/listing/listing.jsx
index 3082c171aa..5583afb2ee 100644
--- a/assets/js/src/listing/listing.jsx
+++ b/assets/js/src/listing/listing.jsx
@@ -369,8 +369,7 @@ const Listing = React.createClass({
   setParams: function () {
     if (this.props.location) {
       const params = Object.keys(this.state)
-        .filter((key) => {
-          return (
+        .filter(key => (
             [
               'group',
               'filter',
@@ -379,8 +378,7 @@ const Listing = React.createClass({
               'sort_by',
               'sort_order',
             ].indexOf(key) !== -1
-          );
-        })
+          ))
         .map((key) => {
           let value = this.state[key];
           if (value === Object(value)) {
@@ -393,7 +391,7 @@ const Listing = React.createClass({
             return `${key}[${value}]`;
           }
         })
-        .filter((key) => { return (key !== undefined); })
+        .filter(key => (key !== undefined))
         .join('/');
 
       // set url
@@ -488,7 +486,7 @@ const Listing = React.createClass({
       }).fail((response) => {
         if (response.errors.length > 0) {
           MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
         }
@@ -518,7 +516,7 @@ const Listing = React.createClass({
       this.getItems();
     }).fail((response) => {
       MailPoet.Notice.error(
-        response.errors.map((error) => { return error.message; }),
+        response.errors.map(error => error.message),
         { scroll: true }
       );
     });
@@ -546,7 +544,7 @@ const Listing = React.createClass({
       this.getItems();
     }).fail((response) => {
       MailPoet.Notice.error(
-        response.errors.map((error) => { return error.message; }),
+        response.errors.map(error => error.message),
         { scroll: true }
       );
     });
@@ -574,7 +572,7 @@ const Listing = React.createClass({
       this.getItems();
     }).fail((response) => {
       MailPoet.Notice.error(
-        response.errors.map((error) => { return error.message; }),
+        response.errors.map(error => error.message),
         { scroll: true }
       );
     });
@@ -591,7 +589,7 @@ const Listing = React.createClass({
       this.handleGroup('all');
     }).fail((response) => {
       MailPoet.Notice.error(
-        response.errors.map((error) => { return error.message; }),
+        response.errors.map(error => error.message),
         { scroll: true }
       );
     });
@@ -630,7 +628,7 @@ const Listing = React.createClass({
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
@@ -679,9 +677,7 @@ const Listing = React.createClass({
     if (is_checked === false) {
       this.clearSelection();
     } else {
-      const selected_ids = this.state.items.map((item) => {
-        return Number(item.id);
-      });
+      const selected_ids = this.state.items.map(item => Number(item.id));
 
       this.setState({
         selected_ids: selected_ids,
@@ -749,9 +745,9 @@ const Listing = React.createClass({
 
     // columns
     let columns = this.props.columns || [];
-    columns = columns.filter((column) => {
-      return (column.display === undefined || !!(column.display) === true);
-    });
+    columns = columns.filter(
+      column => (column.display === undefined || !!(column.display) === true)
+    );
 
     // bulk actions
     let bulk_actions = this.props.bulk_actions || [];
diff --git a/assets/js/src/newsletters/listings/mixins.jsx b/assets/js/src/newsletters/listings/mixins.jsx
index 667baf7775..b1057a9314 100644
--- a/assets/js/src/newsletters/listings/mixins.jsx
+++ b/assets/js/src/newsletters/listings/mixins.jsx
@@ -24,7 +24,7 @@ const QueueMixin = {
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
@@ -44,7 +44,7 @@ const QueueMixin = {
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
@@ -421,7 +421,7 @@ const MailerMixin = {
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
diff --git a/assets/js/src/newsletters/listings/notification.jsx b/assets/js/src/newsletters/listings/notification.jsx
index 5edb9fe02d..2cde6ff8c2 100644
--- a/assets/js/src/newsletters/listings/notification.jsx
+++ b/assets/js/src/newsletters/listings/notification.jsx
@@ -141,7 +141,7 @@ const newsletter_actions = [
       }).fail((response) => {
         if (response.errors.length > 0) {
           MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
         }
@@ -197,9 +197,7 @@ const NewsletterListNotification = React.createClass({
     let sendingFrequency;
 
     // get list of segments' name
-    const segments = newsletter.segments.map((segment) => {
-      return segment.name;
-    });
+    const segments = newsletter.segments.map(segment => segment.name);
     const sendingToSegments = MailPoet.I18n.t('ifNewContentToSegments').replace(
       '%$1s', segments.join(', ')
     );
diff --git a/assets/js/src/newsletters/listings/notification_history.jsx b/assets/js/src/newsletters/listings/notification_history.jsx
index e80795328c..ca831aef26 100644
--- a/assets/js/src/newsletters/listings/notification_history.jsx
+++ b/assets/js/src/newsletters/listings/notification_history.jsx
@@ -64,9 +64,7 @@ const NewsletterListNotificationHistory = React.createClass({
       'has-row-actions'
     );
 
-    const segments = newsletter.segments.map((segment) => {
-      return segment.name;
-    }).join(', ');
+    const segments = newsletter.segments.map(segment => segment.name).join(', ');
 
     return (
       <div>
diff --git a/assets/js/src/newsletters/listings/standard.jsx b/assets/js/src/newsletters/listings/standard.jsx
index 6e03f33836..0286c8980d 100644
--- a/assets/js/src/newsletters/listings/standard.jsx
+++ b/assets/js/src/newsletters/listings/standard.jsx
@@ -156,7 +156,7 @@ let newsletter_actions = [
       }).fail((response) => {
         if (response.errors.length > 0) {
           MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
         }
@@ -180,9 +180,7 @@ const NewsletterListStandard = React.createClass({
       'has-row-actions'
     );
 
-    const segments = newsletter.segments.map((segment) => {
-      return segment.name;
-    }).join(', ');
+    const segments = newsletter.segments.map(segment => segment.name).join(', ');
 
     return (
       <div>
diff --git a/assets/js/src/newsletters/listings/welcome.jsx b/assets/js/src/newsletters/listings/welcome.jsx
index b26ec215df..195d29815c 100644
--- a/assets/js/src/newsletters/listings/welcome.jsx
+++ b/assets/js/src/newsletters/listings/welcome.jsx
@@ -197,9 +197,10 @@ const NewsletterListWelcome = React.createClass({
 
       case 'segment':
         // get segment
-        segment = _.find(mailpoet_segments, (seg) => {
-          return (Number(seg.id) === Number(newsletter.options.segment));
-        });
+        segment = _.find(
+          mailpoet_segments,
+          seg => (Number(seg.id) === Number(newsletter.options.segment))
+        );
 
         if (segment === undefined) {
           return (
diff --git a/assets/js/src/newsletters/scheduling/common.jsx b/assets/js/src/newsletters/scheduling/common.jsx
index 1a3f85ff60..55ed43fccb 100644
--- a/assets/js/src/newsletters/scheduling/common.jsx
+++ b/assets/js/src/newsletters/scheduling/common.jsx
@@ -25,14 +25,12 @@ const TIME_STEP_SECONDS = 3600;
 const numberOfTimeSteps = SECONDS_IN_DAY / TIME_STEP_SECONDS;
 
 const timeOfDayValues = _.object(_.map(
-  _.times(numberOfTimeSteps, (step) => {
-    return step * TIME_STEP_SECONDS;
-  }), (seconds) => {
-  const date = new Date(null);
-  date.setSeconds(seconds);
-  const timeLabel = MailPoet.Date.format(date, { format: timeFormat, offset: 0 });
-  return [seconds, timeLabel];
-})
+  _.times(numberOfTimeSteps, step => step * TIME_STEP_SECONDS), (seconds) => {
+    const date = new Date(null);
+    date.setSeconds(seconds);
+    const timeLabel = MailPoet.Date.format(date, { format: timeFormat, offset: 0 });
+    return [seconds, timeLabel];
+  })
 );
 
 const weekDayValues = {
@@ -48,22 +46,20 @@ const weekDayValues = {
 const NUMBER_OF_DAYS_IN_MONTH = 28;
 const monthDayValues = _.object(
   _.map(
-    _.times(NUMBER_OF_DAYS_IN_MONTH, (day) => {
-      return day;
-    }), (day) => {
-    const labels = {
-      0: MailPoet.I18n.t('first'),
-      1: MailPoet.I18n.t('second'),
-      2: MailPoet.I18n.t('third'),
-    };
-    let label;
-    if (labels[day] !== undefined) {
-      label = labels[day];
-    } else {
-      label = MailPoet.I18n.t('nth').replace('%$1d', day + 1);
+    _.times(NUMBER_OF_DAYS_IN_MONTH, day => day), (day) => {
+      const labels = {
+        0: MailPoet.I18n.t('first'),
+        1: MailPoet.I18n.t('second'),
+        2: MailPoet.I18n.t('third'),
+      };
+      let label;
+      if (labels[day] !== undefined) {
+        label = labels[day];
+      } else {
+        label = MailPoet.I18n.t('nth').replace('%$1d', day + 1);
+      }
+      return [day + 1, label];
     }
-    return [day + 1, label];
-  }
   )
 );
 
diff --git a/assets/js/src/newsletters/send.jsx b/assets/js/src/newsletters/send.jsx
index 1145abab0d..b54057ce68 100644
--- a/assets/js/src/newsletters/send.jsx
+++ b/assets/js/src/newsletters/send.jsx
@@ -194,7 +194,7 @@ define(
             }).fail((response) => {
               if (response.errors.length > 0) {
                 MailPoet.Notice.error(
-                  response.errors.map((error) => { return error.message; }),
+                  response.errors.map(error => error.message),
                   { scroll: true }
                 );
               }
@@ -257,7 +257,7 @@ define(
       showError: (response) => {
         if (response.errors.length > 0) {
           MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
         }
diff --git a/assets/js/src/newsletters/send/notification.jsx b/assets/js/src/newsletters/send/notification.jsx
index 6a20a089b2..fe97da76f0 100644
--- a/assets/js/src/newsletters/send/notification.jsx
+++ b/assets/js/src/newsletters/send/notification.jsx
@@ -46,11 +46,7 @@ define(
         },
         transformChangedValue: function (segment_ids) {
           const all_segments = this.state.items;
-          return _.map(segment_ids, (id) => {
-            return _.find(all_segments, (segment) => {
-              return segment.id === id;
-            });
-          });
+          return _.map(segment_ids, id => _.find(all_segments, segment => segment.id === id));
         },
         validation: {
           'data-parsley-required': true,
diff --git a/assets/js/src/newsletters/send/standard.jsx b/assets/js/src/newsletters/send/standard.jsx
index 182c555ec3..bcca6d5961 100644
--- a/assets/js/src/newsletters/send/standard.jsx
+++ b/assets/js/src/newsletters/send/standard.jsx
@@ -168,15 +168,13 @@ define(
     const TimeSelect = React.createClass({
       render: function () {
         const options = Object.keys(timeOfDayItems).map(
-          (value, index) => {
-            return (
-              <option
-                key={'option-' + index}
-                value={value}>
-                { timeOfDayItems[value] }
-              </option>
-            );
-          }
+          (value, index) => (
+            <option
+              key={'option-' + index}
+              value={value}>
+              { timeOfDayItems[value] }
+            </option>
+            )
         );
 
         return (
@@ -354,11 +352,7 @@ define(
         },
         transformChangedValue: function (segment_ids) {
           const all_segments = this.state.items;
-          return _.map(segment_ids, (id) => {
-            return _.find(all_segments, (segment) => {
-              return segment.id === id;
-            });
-          });
+          return _.map(segment_ids, id => _.find(all_segments, segment => segment.id === id));
         },
         validation: {
           'data-parsley-required': true,
diff --git a/assets/js/src/newsletters/templates.jsx b/assets/js/src/newsletters/templates.jsx
index 0b72b02f2e..079b9cd0fc 100644
--- a/assets/js/src/newsletters/templates.jsx
+++ b/assets/js/src/newsletters/templates.jsx
@@ -29,7 +29,7 @@ const ImportTemplate = React.createClass({
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
@@ -122,7 +122,7 @@ const NewsletterTemplates = React.createClass({
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
@@ -155,7 +155,7 @@ const NewsletterTemplates = React.createClass({
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+          response.errors.map(error => error.message),
           { scroll: true }
         );
       }
@@ -176,7 +176,7 @@ const NewsletterTemplates = React.createClass({
       }).fail((response) => {
         if (response.errors.length > 0) {
           MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
         }
diff --git a/assets/js/src/newsletters/types.jsx b/assets/js/src/newsletters/types.jsx
index e82f170836..6a8d4e1df6 100644
--- a/assets/js/src/newsletters/types.jsx
+++ b/assets/js/src/newsletters/types.jsx
@@ -44,7 +44,7 @@ define(
         }).fail((response) => {
           if (response.errors.length > 0) {
             MailPoet.Notice.error(
-              response.errors.map((error) => { return error.message; }),
+              response.errors.map(error => error.message),
               { scroll: true }
             );
           }
@@ -101,24 +101,22 @@ define(
             <Breadcrumb step="type" />
 
             <ul className="mailpoet_boxes clearfix">
-              {types.map((type, index) => {
-                return (
-                  <li key={index} data-type={type.id}>
-                    <div>
-                      <div className="mailpoet_thumbnail"></div>
+              {types.map((type, index) => (
+                <li key={index} data-type={type.id}>
+                  <div>
+                    <div className="mailpoet_thumbnail"></div>
 
-                      <div className="mailpoet_description">
-                        <h3>{type.title}</h3>
-                        <p>{type.description}</p>
-                      </div>
-
-                      <div className="mailpoet_actions">
-                        {type.action}
-                      </div>
+                    <div className="mailpoet_description">
+                      <h3>{type.title}</h3>
+                      <p>{type.description}</p>
                     </div>
-                  </li>
-                );
-              }, this)}
+
+                    <div className="mailpoet_actions">
+                      {type.action}
+                    </div>
+                  </div>
+                </li>
+                ), this)}
             </ul>
           </div>
         );
diff --git a/assets/js/src/newsletters/types/notification/notification.jsx b/assets/js/src/newsletters/types/notification/notification.jsx
index 93c2fd5c67..d203bfde6d 100644
--- a/assets/js/src/newsletters/types/notification/notification.jsx
+++ b/assets/js/src/newsletters/types/notification/notification.jsx
@@ -55,7 +55,7 @@ define(
         }).fail((response) => {
           if (response.errors.length > 0) {
             MailPoet.Notice.error(
-              response.errors.map((error) => { return error.message; }),
+              response.errors.map(error => error.message),
               { scroll: true }
             );
           }
diff --git a/assets/js/src/newsletters/types/standard.jsx b/assets/js/src/newsletters/types/standard.jsx
index 65f5118e96..f13c544f63 100644
--- a/assets/js/src/newsletters/types/standard.jsx
+++ b/assets/js/src/newsletters/types/standard.jsx
@@ -32,7 +32,7 @@ define(
         }).fail((response) => {
           if (response.errors.length > 0) {
             MailPoet.Notice.error(
-              response.errors.map((error) => { return error.message; }),
+              response.errors.map(error => error.message),
               { scroll: true }
             );
           }
diff --git a/assets/js/src/newsletters/types/welcome/scheduling.jsx b/assets/js/src/newsletters/types/welcome/scheduling.jsx
index dbb44eaea5..89ae72ddb8 100644
--- a/assets/js/src/newsletters/types/welcome/scheduling.jsx
+++ b/assets/js/src/newsletters/types/welcome/scheduling.jsx
@@ -8,9 +8,7 @@ import { timeDelayValues } from 'newsletters/scheduling/common.jsx';
 const availableRoles = window.mailpoet_roles || {};
 const availableSegments = _.filter(
   window.mailpoet_segments || [],
-  (segment) => {
-    return segment.type === 'default';
-  }
+  segment => segment.type === 'default'
 );
 
 const events = {
@@ -113,7 +111,7 @@ const WelcomeScheduling = React.createClass({
     }).fail((response) => {
       if (response.errors.length > 0) {
         MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
       }
diff --git a/assets/js/src/segments/list.jsx b/assets/js/src/segments/list.jsx
index 1d5859a665..5f68afc013 100644
--- a/assets/js/src/segments/list.jsx
+++ b/assets/js/src/segments/list.jsx
@@ -109,26 +109,24 @@ const item_actions = [
   {
     name: 'duplicate_segment',
     label: MailPoet.I18n.t('duplicate'),
-    onClick: (item, refresh) => {
-      return MailPoet.Ajax.post({
-        api_version: window.mailpoet_api_version,
-        endpoint: 'segments',
-        action: 'duplicate',
-        data: {
-          id: item.id,
-        },
-      }).done((response) => {
-        MailPoet.Notice.success(
+    onClick: (item, refresh) => MailPoet.Ajax.post({
+      api_version: window.mailpoet_api_version,
+      endpoint: 'segments',
+      action: 'duplicate',
+      data: {
+        id: item.id,
+      },
+    }).done((response) => {
+      MailPoet.Notice.success(
           MailPoet.I18n.t('listDuplicated').replace('%$1s', response.data.name)
         );
-        refresh();
-      }).fail((response) => {
-        MailPoet.Notice.error(
-          response.errors.map((error) => { return error.message; }),
+      refresh();
+    }).fail((response) => {
+      MailPoet.Notice.error(
+          response.errors.map(error => error.message),
           { scroll: true }
         );
-      });
-    },
+    }),
     display: function (segment) {
       return (segment.type !== 'wp_users');
     },
@@ -166,7 +164,7 @@ const item_actions = [
         MailPoet.Modal.loading(false);
         if (response.errors.length > 0) {
           MailPoet.Notice.error(
-            response.errors.map((error) => { return error.message; }),
+            response.errors.map(error => error.message),
             { scroll: true }
           );
         }