diff --git a/app/javascript/mastodon/components/attachment_list.js b/app/javascript/mastodon/components/attachment_list.js
index 5dfa1464c4..ebd6965835 100644
--- a/app/javascript/mastodon/components/attachment_list.js
+++ b/app/javascript/mastodon/components/attachment_list.js
@@ -25,7 +25,7 @@ export default class AttachmentList extends ImmutablePureComponent {
 
               return (
                 <li key={attachment.get('id')}>
-                  <a href={displayUrl} target='_blank' rel='noopener'><Icon id='link' /> {filename(displayUrl)}</a>
+                  <a href={displayUrl} target='_blank' rel='noopener noreferrer'><Icon id='link' /> {filename(displayUrl)}</a>
                 </li>
               );
             })}
@@ -46,7 +46,7 @@ export default class AttachmentList extends ImmutablePureComponent {
 
             return (
               <li key={attachment.get('id')}>
-                <a href={displayUrl} target='_blank' rel='noopener'>{filename(displayUrl)}</a>
+                <a href={displayUrl} target='_blank' rel='noopener noreferrer'>{filename(displayUrl)}</a>
               </li>
             );
           })}
diff --git a/app/javascript/mastodon/components/dropdown_menu.js b/app/javascript/mastodon/components/dropdown_menu.js
index d423378c11..a4f2622851 100644
--- a/app/javascript/mastodon/components/dropdown_menu.js
+++ b/app/javascript/mastodon/components/dropdown_menu.js
@@ -143,7 +143,7 @@ class DropdownMenu extends React.PureComponent {
 
     return (
       <li className='dropdown-menu__item' key={`${text}-${i}`}>
-        <a href={href} target={target} data-method={method} rel='noopener' role='button' tabIndex='0' ref={i === 0 ? this.setFocusRef : null} onClick={this.handleClick} onKeyPress={this.handleItemKeyPress} data-index={i}>
+        <a href={href} target={target} data-method={method} rel='noopener noreferrer' role='button' tabIndex='0' ref={i === 0 ? this.setFocusRef : null} onClick={this.handleClick} onKeyPress={this.handleItemKeyPress} data-index={i}>
           {text}
         </a>
       </li>
diff --git a/app/javascript/mastodon/components/error_boundary.js b/app/javascript/mastodon/components/error_boundary.js
index 82543e1185..800b1c2706 100644
--- a/app/javascript/mastodon/components/error_boundary.js
+++ b/app/javascript/mastodon/components/error_boundary.js
@@ -58,7 +58,7 @@ export default class ErrorBoundary extends React.PureComponent {
         <div>
           <p className='error-boundary__error'><FormattedMessage id='error.unexpected_crash.explanation' defaultMessage='Due to a bug in our code or a browser compatibility issue, this page could not be displayed correctly.' /></p>
           <p><FormattedMessage id='error.unexpected_crash.next_steps' defaultMessage='Try refreshing the page. If that does not help, you may still be able to use Mastodon through a different browser or native app.' /></p>
-          <p className='error-boundary__footer'>Mastodon v{version} · <a href={source_url} rel='noopener' target='_blank'><FormattedMessage id='errors.unexpected_crash.report_issue' defaultMessage='Report issue' /></a> · <button onClick={this.handleCopyStackTrace} className={copied && 'copied'}><FormattedMessage id='errors.unexpected_crash.copy_stacktrace' defaultMessage='Copy stacktrace to clipboard' /></button></p>
+          <p className='error-boundary__footer'>Mastodon v{version} · <a href={source_url} rel='noopener noreferrer' target='_blank'><FormattedMessage id='errors.unexpected_crash.report_issue' defaultMessage='Report issue' /></a> · <button onClick={this.handleCopyStackTrace} className={copied && 'copied'}><FormattedMessage id='errors.unexpected_crash.copy_stacktrace' defaultMessage='Copy stacktrace to clipboard' /></button></p>
         </div>
       </div>
     );
diff --git a/app/javascript/mastodon/components/media_gallery.js b/app/javascript/mastodon/components/media_gallery.js
index e8dd79af9e..b8fca8bcb5 100644
--- a/app/javascript/mastodon/components/media_gallery.js
+++ b/app/javascript/mastodon/components/media_gallery.js
@@ -159,7 +159,7 @@ class Item extends React.PureComponent {
     if (attachment.get('type') === 'unknown') {
       return (
         <div className={classNames('media-gallery__item', { standalone })} key={attachment.get('id')} style={{ left: left, top: top, right: right, bottom: bottom, width: `${width}%`, height: `${height}%` }}>
-          <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url') || attachment.get('url')} target='_blank' style={{ cursor: 'pointer' }} title={attachment.get('description')}>
+          <a className='media-gallery__item-thumbnail' href={attachment.get('remote_url') || attachment.get('url')} style={{ cursor: 'pointer' }} title={attachment.get('description')} target='_blank' rel='noopener noreferrer'>
             <canvas width={32} height={32} ref={this.setCanvasRef} className='media-gallery__preview' />
           </a>
         </div>
@@ -187,6 +187,7 @@ class Item extends React.PureComponent {
           href={attachment.get('remote_url') || originalUrl}
           onClick={this.handleClick}
           target='_blank'
+          rel='noopener noreferrer'
         >
           <img
             src={previewUrl}
diff --git a/app/javascript/mastodon/components/status.js b/app/javascript/mastodon/components/status.js
index b5606aca5a..6cfa96040b 100644
--- a/app/javascript/mastodon/components/status.js
+++ b/app/javascript/mastodon/components/status.js
@@ -437,9 +437,9 @@ class Status extends ImmutablePureComponent {
           <div className={classNames('status', `status-${status.get('visibility')}`, { 'status-reply': !!status.get('in_reply_to_id'), muted: this.props.muted, read: unread === false })} data-id={status.get('id')}>
             <div className='status__expand' onClick={this.handleExpandClick} role='presentation' />
             <div className='status__info'>
-              <a href={status.get('url')} className='status__relative-time' target='_blank' rel='noopener'><RelativeTimestamp timestamp={status.get('created_at')} /></a>
+              <a href={status.get('url')} className='status__relative-time' target='_blank' rel='noopener noreferrer'><RelativeTimestamp timestamp={status.get('created_at')} /></a>
 
-              <a onClick={this.handleAccountClick} target='_blank' data-id={status.getIn(['account', 'id'])} href={status.getIn(['account', 'url'])} title={status.getIn(['account', 'acct'])} className='status__display-name'>
+              <a onClick={this.handleAccountClick} data-id={status.getIn(['account', 'id'])} href={status.getIn(['account', 'url'])} title={status.getIn(['account', 'acct'])} className='status__display-name' target='_blank' rel='noopener noreferrer'>
                 <div className='status__avatar'>
                   {statusAvatar}
                 </div>
diff --git a/app/javascript/mastodon/components/status_content.js b/app/javascript/mastodon/components/status_content.js
index 4ce9ec49f3..d13091325b 100644
--- a/app/javascript/mastodon/components/status_content.js
+++ b/app/javascript/mastodon/components/status_content.js
@@ -59,7 +59,7 @@ export default class StatusContent extends React.PureComponent {
       }
 
       link.setAttribute('target', '_blank');
-      link.setAttribute('rel', 'noopener');
+      link.setAttribute('rel', 'noopener noreferrer');
     }
 
     if (
diff --git a/app/javascript/mastodon/features/account/components/header.js b/app/javascript/mastodon/features/account/components/header.js
index ac97bad712..dbb567e85e 100644
--- a/app/javascript/mastodon/features/account/components/header.js
+++ b/app/javascript/mastodon/features/account/components/header.js
@@ -253,7 +253,7 @@ class Header extends ImmutablePureComponent {
 
         <div className='account__header__bar'>
           <div className='account__header__tabs'>
-            <a className='avatar' href={account.get('url')} rel='noopener' target='_blank'>
+            <a className='avatar' href={account.get('url')} rel='noopener noreferrer' target='_blank'>
               <Avatar account={account} size={90} />
             </a>
 
@@ -282,10 +282,10 @@ class Header extends ImmutablePureComponent {
                       <dt dangerouslySetInnerHTML={{ __html: proof.get('provider') }} />
 
                       <dd className='verified'>
-                        <a href={proof.get('proof_url')} target='_blank' rel='noopener'><span title={intl.formatMessage(messages.linkVerifiedOn, { date: intl.formatDate(proof.get('updated_at'), dateFormatOptions) })}>
+                        <a href={proof.get('proof_url')} target='_blank' rel='noopener noreferrer'><span title={intl.formatMessage(messages.linkVerifiedOn, { date: intl.formatDate(proof.get('updated_at'), dateFormatOptions) })}>
                           <Icon id='check' className='verified__mark' />
                         </span></a>
-                        <a href={proof.get('profile_url')} target='_blank' rel='noopener'><span dangerouslySetInnerHTML={{ __html: ' '+proof.get('provider_username') }} /></a>
+                        <a href={proof.get('profile_url')} target='_blank' rel='noopener noreferrer'><span dangerouslySetInnerHTML={{ __html: ' '+proof.get('provider_username') }} /></a>
                       </dd>
                     </dl>
                   ))}
diff --git a/app/javascript/mastodon/features/account_gallery/components/media_item.js b/app/javascript/mastodon/features/account_gallery/components/media_item.js
index b6eec22439..617a45d165 100644
--- a/app/javascript/mastodon/features/account_gallery/components/media_item.js
+++ b/app/javascript/mastodon/features/account_gallery/components/media_item.js
@@ -1,12 +1,12 @@
-import React from 'react';
-import PropTypes from 'prop-types';
-import ImmutablePropTypes from 'react-immutable-proptypes';
-import ImmutablePureComponent from 'react-immutable-pure-component';
+import { decode } from 'blurhash';
+import classNames from 'classnames';
 import Icon from 'mastodon/components/icon';
 import { autoPlayGif, displayMedia } from 'mastodon/initial_state';
-import classNames from 'classnames';
-import { decode } from 'blurhash';
 import { isIOS } from 'mastodon/is_mobile';
+import PropTypes from 'prop-types';
+import React from 'react';
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import ImmutablePureComponent from 'react-immutable-pure-component';
 
 export default class MediaItem extends ImmutablePureComponent {
 
@@ -151,7 +151,7 @@ export default class MediaItem extends ImmutablePureComponent {
 
     return (
       <div className='account-gallery__item' style={{ width, height }}>
-        <a className='media-gallery__item-thumbnail' href={status.get('url')} target='_blank' onClick={this.handleClick} title={title}>
+        <a className='media-gallery__item-thumbnail' href={status.get('url')} onClick={this.handleClick} title={title} target='_blank' rel='noopener noreferrer'>
           <canvas width={32} height={32} ref={this.setCanvasRef} className={classNames('media-gallery__preview', { 'media-gallery__preview--hidden': visible && loaded })} />
           {visible && thumbnail}
           {!visible && icon}
diff --git a/app/javascript/mastodon/features/status/components/card.js b/app/javascript/mastodon/features/status/components/card.js
index 0eff544119..2993fe29aa 100644
--- a/app/javascript/mastodon/features/status/components/card.js
+++ b/app/javascript/mastodon/features/status/components/card.js
@@ -148,7 +148,7 @@ export default class Card extends React.PureComponent {
     const horizontal  = (!compact && card.get('width') > card.get('height') && (card.get('width') + 100 >= width)) || card.get('type') !== 'link' || embedded;
     const interactive = card.get('type') !== 'link';
     const className   = classnames('status-card', { horizontal, compact, interactive });
-    const title       = interactive ? <a className='status-card__title' href={card.get('url')} title={card.get('title')} rel='noopener' target='_blank'><strong>{card.get('title')}</strong></a> : <strong className='status-card__title' title={card.get('title')}>{card.get('title')}</strong>;
+    const title       = interactive ? <a className='status-card__title' href={card.get('url')} title={card.get('title')} rel='noopener noreferrer' target='_blank'><strong>{card.get('title')}</strong></a> : <strong className='status-card__title' title={card.get('title')}>{card.get('title')}</strong>;
     const ratio       = card.get('width') / card.get('height');
     const height      = (compact && !embedded) ? (width / (16 / 9)) : (width / ratio);
 
@@ -180,7 +180,7 @@ export default class Card extends React.PureComponent {
             <div className='status-card__actions'>
               <div>
                 <button onClick={this.handleEmbedClick}><Icon id={iconVariant} /></button>
-                {horizontal && <a href={card.get('url')} target='_blank' rel='noopener'><Icon id='external-link' /></a>}
+                {horizontal && <a href={card.get('url')} target='_blank' rel='noopener noreferrer'><Icon id='external-link' /></a>}
               </div>
             </div>
           </div>
@@ -208,7 +208,7 @@ export default class Card extends React.PureComponent {
     }
 
     return (
-      <a href={card.get('url')} className={className} target='_blank' rel='noopener' ref={this.setRef}>
+      <a href={card.get('url')} className={className} target='_blank' rel='noopener noreferrer' ref={this.setRef}>
         {embed}
         {description}
       </a>
diff --git a/app/javascript/mastodon/features/status/components/detailed_status.js b/app/javascript/mastodon/features/status/components/detailed_status.js
index e97f18f08c..d5bc827359 100644
--- a/app/javascript/mastodon/features/status/components/detailed_status.js
+++ b/app/javascript/mastodon/features/status/components/detailed_status.js
@@ -156,7 +156,7 @@ export default class DetailedStatus extends ImmutablePureComponent {
     }
 
     if (status.get('application')) {
-      applicationLink = <span> · <a className='detailed-status__application' href={status.getIn(['application', 'website'])} target='_blank' rel='noopener'>{status.getIn(['application', 'name'])}</a></span>;
+      applicationLink = <span> · <a className='detailed-status__application' href={status.getIn(['application', 'website'])} target='_blank' rel='noopener noreferrer'>{status.getIn(['application', 'name'])}</a></span>;
     }
 
     if (status.get('visibility') === 'direct') {
@@ -220,7 +220,7 @@ export default class DetailedStatus extends ImmutablePureComponent {
           {media}
 
           <div className='detailed-status__meta'>
-            <a className='detailed-status__datetime' href={status.get('url')} target='_blank' rel='noopener'>
+            <a className='detailed-status__datetime' href={status.get('url')} target='_blank' rel='noopener noreferrer'>
               <FormattedDate value={new Date(status.get('created_at'))} hour12={false} year='numeric' month='short' day='2-digit' hour='2-digit' minute='2-digit' />
             </a>{applicationLink} · {reblogLink} · {favouriteLink}
           </div>
diff --git a/app/javascript/mastodon/features/ui/components/actions_modal.js b/app/javascript/mastodon/features/ui/components/actions_modal.js
index 00280f7a68..875b2b75d7 100644
--- a/app/javascript/mastodon/features/ui/components/actions_modal.js
+++ b/app/javascript/mastodon/features/ui/components/actions_modal.js
@@ -26,7 +26,7 @@ export default class ActionsModal extends ImmutablePureComponent {
 
     return (
       <li key={`${text}-${i}`}>
-        <a href={href} target='_blank' rel='noopener' onClick={this.props.onClick} data-index={i} className={classNames({ active })}>
+        <a href={href} target='_blank' rel='noopener noreferrer' onClick={this.props.onClick} data-index={i} className={classNames({ active })}>
           {icon && <IconButton title={text} icon={icon} role='presentation' tabIndex='-1' inverted />}
           <div>
             <div className={classNames({ 'actions-modal__item-label': !!meta })}>{text}</div>
@@ -42,7 +42,7 @@ export default class ActionsModal extends ImmutablePureComponent {
       <div className='status light'>
         <div className='boost-modal__status-header'>
           <div className='boost-modal__status-time'>
-            <a href={this.props.status.get('url')} className='status__relative-time' target='_blank' rel='noopener'>
+            <a href={this.props.status.get('url')} className='status__relative-time' target='_blank' rel='noopener noreferrer'>
               <RelativeTimestamp timestamp={this.props.status.get('created_at')} />
             </a>
           </div>
diff --git a/app/javascript/mastodon/features/ui/components/boost_modal.js b/app/javascript/mastodon/features/ui/components/boost_modal.js
index 70f4a1282e..0e79005f04 100644
--- a/app/javascript/mastodon/features/ui/components/boost_modal.js
+++ b/app/javascript/mastodon/features/ui/components/boost_modal.js
@@ -61,7 +61,7 @@ class BoostModal extends ImmutablePureComponent {
           <div className='status light'>
             <div className='boost-modal__status-header'>
               <div className='boost-modal__status-time'>
-                <a href={status.get('url')} className='status__relative-time' target='_blank' rel='noopener'><RelativeTimestamp timestamp={status.get('created_at')} /></a>
+                <a href={status.get('url')} className='status__relative-time' target='_blank' rel='noopener noreferrer'><RelativeTimestamp timestamp={status.get('created_at')} /></a>
               </div>
 
               <a onClick={this.handleAccountClick} href={status.getIn(['account', 'url'])} className='status__display-name'>
diff --git a/app/javascript/mastodon/features/ui/components/link_footer.js b/app/javascript/mastodon/features/ui/components/link_footer.js
index 2b9bd3875e..3c4cff9f9c 100644
--- a/app/javascript/mastodon/features/ui/components/link_footer.js
+++ b/app/javascript/mastodon/features/ui/components/link_footer.js
@@ -62,7 +62,7 @@ class LinkFooter extends React.PureComponent {
           <FormattedMessage
             id='getting_started.open_source_notice'
             defaultMessage='Mastodon is open source software. You can contribute or report issues on GitHub at {github}.'
-            values={{ github: <span><a href={source_url} rel='noopener' target='_blank'>{repository}</a> (v{version})</span> }}
+            values={{ github: <span><a href={source_url} rel='noopener noreferrer' target='_blank'>{repository}</a> (v{version})</span> }}
           />
         </p>
       </div>
diff --git a/app/lib/formatter.rb b/app/lib/formatter.rb
index 990b9f63ed..6ba3276141 100644
--- a/app/lib/formatter.rb
+++ b/app/lib/formatter.rb
@@ -251,7 +251,7 @@ class Formatter
 
   def link_to_url(entity, options = {})
     url        = Addressable::URI.parse(entity[:url])
-    html_attrs = { target: '_blank', rel: 'nofollow noopener' }
+    html_attrs = { target: '_blank', rel: 'nofollow noopener noreferrer' }
 
     html_attrs[:rel] = "me #{html_attrs[:rel]}" if options[:me]
 
diff --git a/app/lib/sanitize_config.rb b/app/lib/sanitize_config.rb
index aba8ce9f61..77045155e0 100644
--- a/app/lib/sanitize_config.rb
+++ b/app/lib/sanitize_config.rb
@@ -45,7 +45,7 @@ class Sanitize
 
       add_attributes: {
         'a' => {
-          'rel' => 'nofollow noopener',
+          'rel' => 'nofollow noopener noreferrer',
           'target' => '_blank',
         },
       },
diff --git a/app/views/about/show.html.haml b/app/views/about/show.html.haml
index 80f4cd8287..e0ec98ec97 100644
--- a/app/views/about/show.html.haml
+++ b/app/views/about/show.html.haml
@@ -38,7 +38,7 @@
                 %small= t('about.browse_public_posts')
 
         .directory__tag
-          = link_to 'https://joinmastodon.org/apps', target: '_blank', rel: 'noopener' do
+          = link_to 'https://joinmastodon.org/apps', target: '_blank', rel: 'noopener noreferrer' do
             %h4
               = fa_icon 'tablet fw'
               = t('about.get_apps')
diff --git a/app/views/accounts/_moved.html.haml b/app/views/accounts/_moved.html.haml
index 02fd7bf429..a82f277b16 100644
--- a/app/views/accounts/_moved.html.haml
+++ b/app/views/accounts/_moved.html.haml
@@ -6,7 +6,7 @@
     = t('accounts.moved_html', name: content_tag(:bdi, content_tag(:strong, display_name(account, custom_emojify: true), class: :emojify)), new_profile_link: link_to(content_tag(:strong, safe_join(['@', content_tag(:span, moved_to_account.acct)])), ActivityPub::TagManager.instance.url_for(moved_to_account), class: 'mention'))
 
   .moved-account-widget__card
-    = link_to ActivityPub::TagManager.instance.url_for(moved_to_account), class: 'detailed-status__display-name p-author h-card', target: '_blank', rel: 'me noopener' do
+    = link_to ActivityPub::TagManager.instance.url_for(moved_to_account), class: 'detailed-status__display-name p-author h-card', target: '_blank', rel: 'me noopener noreferrer' do
       .detailed-status__display-avatar
         .account__avatar-overlay
           .account__avatar-overlay-base{ style: "background-image: url('#{moved_to_account.avatar.url(:original)}')" }
diff --git a/app/views/admin/reports/_status.html.haml b/app/views/admin/reports/_status.html.haml
index 6facc0a568..425d315e17 100644
--- a/app/views/admin/reports/_status.html.haml
+++ b/app/views/admin/reports/_status.html.haml
@@ -19,7 +19,7 @@
         = react_component :media_gallery, height: 343, sensitive: !current_account&.user&.show_all_media? && status.proper.sensitive? || current_account&.user&.hide_all_media?, 'autoPlayGif': current_account&.user&.setting_auto_play_gif, media: status.proper.media_attachments.map { |a| ActiveModelSerializers::SerializableResource.new(a, serializer: REST::MediaAttachmentSerializer).as_json }
 
     .detailed-status__meta
-      = link_to ActivityPub::TagManager.instance.url_for(status), class: 'detailed-status__datetime', target: stream_link_target, rel: 'noopener' do
+      = link_to ActivityPub::TagManager.instance.url_for(status), class: 'detailed-status__datetime', target: stream_link_target, rel: 'noopener noreferrer' do
         %time.formatted{ datetime: status.created_at.iso8601, title: l(status.created_at) }= l(status.created_at)
       - if status.discarded?
         ·
diff --git a/app/views/admin/tags/show.html.haml b/app/views/admin/tags/show.html.haml
index 5799e5973d..c9a147587c 100644
--- a/app/views/admin/tags/show.html.haml
+++ b/app/views/admin/tags/show.html.haml
@@ -3,7 +3,7 @@
 
 .dashboard__counters
   %div
-    = link_to tag_url(@tag), target: '_blank', rel: 'noopener' do
+    = link_to tag_url(@tag), target: '_blank', rel: 'noopener noreferrer' do
       .dashboard__counters__num= number_with_delimiter @accounts_today
       .dashboard__counters__label= t 'admin.tags.accounts_today'
   %div
diff --git a/app/views/application/_card.html.haml b/app/views/application/_card.html.haml
index 8719ce4844..808dce5144 100644
--- a/app/views/application/_card.html.haml
+++ b/app/views/application/_card.html.haml
@@ -1,7 +1,7 @@
 - account_url = local_assigns[:admin] ? admin_account_path(account.id) : ActivityPub::TagManager.instance.url_for(account)
 
 .card.h-card
-  = link_to account_url, target: '_blank', rel: 'noopener' do
+  = link_to account_url, target: '_blank', rel: 'noopener noreferrer' do
     .card__img
       = image_tag account.header.url, alt: ''
     .card__bar
diff --git a/app/views/oauth/authorized_applications/index.html.haml b/app/views/oauth/authorized_applications/index.html.haml
index 7203d758da..7b77108a93 100644
--- a/app/views/oauth/authorized_applications/index.html.haml
+++ b/app/views/oauth/authorized_applications/index.html.haml
@@ -16,7 +16,7 @@
             - if application.website.blank?
               = application.name
             - else
-              = link_to application.name, application.website, target: '_blank', rel: 'noopener'
+              = link_to application.name, application.website, target: '_blank', rel: 'noopener noreferrer'
           %th!= application.scopes.map { |scope| t(scope, scope: [:doorkeeper, :scopes]) }.join(', ')
           %td= l application.created_at
           %td
diff --git a/app/views/statuses/_detailed_status.html.haml b/app/views/statuses/_detailed_status.html.haml
index 5cee84ada8..3fa52d3f2b 100644
--- a/app/views/statuses/_detailed_status.html.haml
+++ b/app/views/statuses/_detailed_status.html.haml
@@ -44,14 +44,14 @@
   .detailed-status__meta
     %data.dt-published{ value: status.created_at.to_time.iso8601 }
 
-    = link_to ActivityPub::TagManager.instance.url_for(status), class: 'detailed-status__datetime u-url u-uid', target: stream_link_target, rel: 'noopener' do
+    = link_to ActivityPub::TagManager.instance.url_for(status), class: 'detailed-status__datetime u-url u-uid', target: stream_link_target, rel: 'noopener noreferrer' do
       %time.formatted{ datetime: status.created_at.iso8601, title: l(status.created_at) }= l(status.created_at)
     ·
     - if status.application && @account.user&.setting_show_application
       - if status.application.website.blank?
         %strong.detailed-status__application= status.application.name
       - else
-        = link_to status.application.name, status.application.website, class: 'detailed-status__application', target: '_blank', rel: 'noopener'
+        = link_to status.application.name, status.application.website, class: 'detailed-status__application', target: '_blank', rel: 'noopener noreferrer'
       ·
     = link_to remote_interaction_path(status, type: :reply), class: 'modal-button detailed-status__link' do
       - if status.in_reply_to_id.nil?
diff --git a/app/views/statuses/_simple_status.html.haml b/app/views/statuses/_simple_status.html.haml
index a68fe10220..edcfbba2bf 100644
--- a/app/views/statuses/_simple_status.html.haml
+++ b/app/views/statuses/_simple_status.html.haml
@@ -1,11 +1,11 @@
 .status
   .status__info
-    = link_to ActivityPub::TagManager.instance.url_for(status), class: 'status__relative-time u-url u-uid', target: stream_link_target, rel: 'noopener' do
+    = link_to ActivityPub::TagManager.instance.url_for(status), class: 'status__relative-time u-url u-uid', target: stream_link_target, rel: 'noopener noreferrer' do
       %time.time-ago{ datetime: status.created_at.iso8601, title: l(status.created_at) }= l(status.created_at)
     %data.dt-published{ value: status.created_at.to_time.iso8601 }
 
     .p-author.h-card
-      = link_to ActivityPub::TagManager.instance.url_for(status.account), class: 'status__display-name u-url', target: stream_link_target, rel: 'noopener' do
+      = link_to ActivityPub::TagManager.instance.url_for(status.account), class: 'status__display-name u-url', target: stream_link_target, rel: 'noopener noreferrer' do
         .status__avatar
           %div
             - if current_account&.user&.setting_auto_play_gif || autoplay
diff --git a/spec/fixtures/xml/mastodon.atom b/spec/fixtures/xml/mastodon.atom
index 9ece3bc2e3..92921a9380 100644
--- a/spec/fixtures/xml/mastodon.atom
+++ b/spec/fixtures/xml/mastodon.atom
@@ -123,7 +123,7 @@
     <published>2016-10-10T00:41:31Z</published>
     <updated>2016-10-10T00:41:31Z</updated>
     <title>Social media needs MOAR cats! http://kickass.zone/media/3</title>
-    <content type="html">&lt;p&gt;Social media needs MOAR cats! &lt;a rel="nofollow noopener" href="http://kickass.zone/media/3"&gt;http://kickass.zone/media/3&lt;/a&gt;&lt;/p&gt;</content>
+    <content type="html">&lt;p&gt;Social media needs MOAR cats! &lt;a rel="nofollow noopener noreferrer" href="http://kickass.zone/media/3"&gt;http://kickass.zone/media/3&lt;/a&gt;&lt;/p&gt;</content>
     <activity:verb>http://activitystrea.ms/schema/1.0/post</activity:verb>
     <link rel="self" type="application/atom+xml" href="http://kickass.zone/users/localhost/updates/9.atom"/>
     <link rel="alternate" type="text/html" href="http://kickass.zone/users/localhost/updates/9"/>
@@ -135,7 +135,7 @@
     <published>2016-10-10T00:38:39Z</published>
     <updated>2016-10-10T00:38:39Z</updated>
     <title>http://kickass.zone/media/2</title>
-    <content type="html">&lt;p&gt;&lt;a rel="nofollow noopener" href="http://kickass.zone/media/2"&gt;http://kickass.zone/media/2&lt;/a&gt;&lt;/p&gt;</content>
+    <content type="html">&lt;p&gt;&lt;a rel="nofollow noopener noreferrer" href="http://kickass.zone/media/2"&gt;http://kickass.zone/media/2&lt;/a&gt;&lt;/p&gt;</content>
     <activity:verb>http://activitystrea.ms/schema/1.0/post</activity:verb>
     <link rel="self" type="application/atom+xml" href="http://kickass.zone/users/localhost/updates/8.atom"/>
     <link rel="alternate" type="text/html" href="http://kickass.zone/users/localhost/updates/8"/>
diff --git a/spec/lib/sanitize_config_spec.rb b/spec/lib/sanitize_config_spec.rb
index 54bd8693cc..feb86af352 100644
--- a/spec/lib/sanitize_config_spec.rb
+++ b/spec/lib/sanitize_config_spec.rb
@@ -24,7 +24,7 @@ describe Sanitize::Config do
     end
 
     it 'keep links in lists' do
-      expect(Sanitize.fragment('<p>Check out:</p><ul><li><a href="https://joinmastodon.org" rel="nofollow noopener" target="_blank">joinmastodon.org</a></li><li>Bar</li></ul>', subject)).to eq '<p>Check out:</p><p><a href="https://joinmastodon.org" rel="nofollow noopener" target="_blank">joinmastodon.org</a><br>Bar</p>'
+      expect(Sanitize.fragment('<p>Check out:</p><ul><li><a href="https://joinmastodon.org" rel="nofollow noopener noreferrer" target="_blank">joinmastodon.org</a></li><li>Bar</li></ul>', subject)).to eq '<p>Check out:</p><p><a href="https://joinmastodon.org" rel="nofollow noopener noreferrer" target="_blank">joinmastodon.org</a><br>Bar</p>'
     end
   end
 end
diff --git a/spec/services/fetch_link_card_service_spec.rb b/spec/services/fetch_link_card_service_spec.rb
index 9761c5f064..3c8f6f578f 100644
--- a/spec/services/fetch_link_card_service_spec.rb
+++ b/spec/services/fetch_link_card_service_spec.rb
@@ -80,7 +80,7 @@ RSpec.describe FetchLinkCardService, type: :service do
   end
 
   context 'in a remote status' do
-    let(:status) { Fabricate(:status, account: Fabricate(:account, domain: 'example.com'), text: 'Habt ihr ein paar gute Links zu #<span class="tag"><a href="https://quitter.se/tag/wannacry" target="_blank" rel="tag noopener" title="https://quitter.se/tag/wannacry">Wannacry</a></span> herumfliegen?   Ich will mal unter <br> <a href="https://github.com/qbi/WannaCry" target="_blank" rel="noopener" title="https://github.com/qbi/WannaCry">https://github.com/qbi/WannaCry</a> was sammeln. !<a href="http://sn.jonkman.ca/group/416/id" target="_blank" rel="noopener" title="http://sn.jonkman.ca/group/416/id">security</a>&nbsp;') }
+    let(:status) { Fabricate(:status, account: Fabricate(:account, domain: 'example.com'), text: 'Habt ihr ein paar gute Links zu #<span class="tag"><a href="https://quitter.se/tag/wannacry" target="_blank" rel="tag noopener noreferrer" title="https://quitter.se/tag/wannacry">Wannacry</a></span> herumfliegen?   Ich will mal unter <br> <a href="https://github.com/qbi/WannaCry" target="_blank" rel="noopener noreferrer" title="https://github.com/qbi/WannaCry">https://github.com/qbi/WannaCry</a> was sammeln. !<a href="http://sn.jonkman.ca/group/416/id" target="_blank" rel="noopener noreferrer" title="http://sn.jonkman.ca/group/416/id">security</a>&nbsp;') }
 
     it 'parses out URLs' do
       expect(a_request(:get, 'https://github.com/qbi/WannaCry')).to have_been_made.at_least_once
diff --git a/spec/services/verify_link_service_spec.rb b/spec/services/verify_link_service_spec.rb
index 2edcdb75f1..3fc88e60e4 100644
--- a/spec/services/verify_link_service_spec.rb
+++ b/spec/services/verify_link_service_spec.rb
@@ -28,12 +28,12 @@ RSpec.describe VerifyLinkService, type: :service do
       end
     end
 
-    context 'when a link contains an <a rel="noopener"> back' do
+    context 'when a link contains an <a rel="noopener noreferrer"> back' do
       let(:html) do
         <<-HTML
           <!doctype html>
           <body>
-            <a href="#{ActivityPub::TagManager.instance.url_for(account)}" rel="noopener me" target="_blank">Follow me on Mastodon</a>
+            <a href="#{ActivityPub::TagManager.instance.url_for(account)}" rel="me noopener noreferrer" target="_blank">Follow me on Mastodon</a>
           </body>
         HTML
       end