diff --git a/.eslintrc.js b/.eslintrc.js
index ca7fc83eb9..ef52818b06 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -98,7 +98,6 @@ module.exports = {
         ignoreRestSiblings: true,
       },
     ],
-    'no-useless-escape': 'off',
     'object-curly-spacing': ['error', 'always'],
     'padded-blocks': [
       'error',
diff --git a/app/javascript/mastodon/actions/push_notifications/registerer.js b/app/javascript/mastodon/actions/push_notifications/registerer.js
index b0f42b6a20..b491f85c24 100644
--- a/app/javascript/mastodon/actions/push_notifications/registerer.js
+++ b/app/javascript/mastodon/actions/push_notifications/registerer.js
@@ -8,7 +8,7 @@ import { me } from '../../initial_state';
 const urlBase64ToUint8Array = (base64String) => {
   const padding = '='.repeat((4 - base64String.length % 4) % 4);
   const base64 = (base64String + padding)
-    .replace(/\-/g, '+')
+    .replace(/-/g, '+')
     .replace(/_/g, '/');
 
   return decodeBase64(base64);
diff --git a/app/javascript/mastodon/components/status.js b/app/javascript/mastodon/components/status.js
index 6b89226085..f02910f5ac 100644
--- a/app/javascript/mastodon/components/status.js
+++ b/app/javascript/mastodon/components/status.js
@@ -511,7 +511,7 @@ class Status extends ImmutablePureComponent {
 
           <div className={classNames('status', `status-${status.get('visibility')}`, { 'status-reply': !!status.get('in_reply_to_id'), muted: this.props.muted })} data-id={status.get('id')}>
             <div className='status__info'>
-              <a onClick={this.handleClick} href={`/@${status.getIn(['account', 'acct'])}\/${status.get('id')}`} className='status__relative-time' target='_blank' rel='noopener noreferrer'>
+              <a onClick={this.handleClick} href={`/@${status.getIn(['account', 'acct'])}/${status.get('id')}`} className='status__relative-time' target='_blank' rel='noopener noreferrer'>
                 <span className='status__visibility-icon'><Icon id={visibilityIcon.icon} title={visibilityIcon.text} /></span>
                 <RelativeTimestamp timestamp={status.get('created_at')} />{status.get('edited_at') && <abbr title={intl.formatMessage(messages.edited, { date: intl.formatDate(status.get('edited_at'), { hour12: false, year: 'numeric', month: 'short', day: '2-digit', hour: '2-digit', minute: '2-digit' }) })}> *</abbr>}
               </a>
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 80e164af89..d6d60ebda7 100644
--- a/app/javascript/mastodon/features/account_gallery/components/media_item.js
+++ b/app/javascript/mastodon/features/account_gallery/components/media_item.js
@@ -130,7 +130,7 @@ export default class MediaItem extends ImmutablePureComponent {
 
     return (
       <div className='account-gallery__item' style={{ width, height }}>
-        <a className='media-gallery__item-thumbnail' href={`/@${status.getIn(['account', 'acct'])}\/${status.get('id')}`} onClick={this.handleClick} title={title} target='_blank' rel='noopener noreferrer'>
+        <a className='media-gallery__item-thumbnail' href={`/@${status.getIn(['account', 'acct'])}/${status.get('id')}`} onClick={this.handleClick} title={title} target='_blank' rel='noopener noreferrer'>
           <Blurhash
             hash={attachment.get('blurhash')}
             className={classNames('media-gallery__preview', { 'media-gallery__preview--hidden': visible && loaded })}
diff --git a/app/javascript/mastodon/features/compose/containers/warning_container.js b/app/javascript/mastodon/features/compose/containers/warning_container.js
index 571d1d8382..3c6ed483d0 100644
--- a/app/javascript/mastodon/features/compose/containers/warning_container.js
+++ b/app/javascript/mastodon/features/compose/containers/warning_container.js
@@ -24,7 +24,7 @@ const buildHashtagRE = () => {
       '))', 'iu',
     );
   } catch {
-    return /(?:^|[^\/\)\w])#(\w*[a-zA-Z·]\w*)/i;
+    return /(?:^|[^/)\w])#(\w*[a-zA-Z·]\w*)/i;
   }
 };
 
diff --git a/app/javascript/mastodon/features/compose/util/counter.js b/app/javascript/mastodon/features/compose/util/counter.js
index 5a68bad992..ec2431096b 100644
--- a/app/javascript/mastodon/features/compose/util/counter.js
+++ b/app/javascript/mastodon/features/compose/util/counter.js
@@ -5,5 +5,5 @@ const urlPlaceholder = '$2xxxxxxxxxxxxxxxxxxxxxxx';
 export function countableText(inputText) {
   return inputText
     .replace(urlRegex, urlPlaceholder)
-    .replace(/(^|[^\/\w])@(([a-z0-9_]+)@[a-z0-9\.\-]+[a-z0-9]+)/ig, '$1@$3');
+    .replace(/(^|[^/\w])@(([a-z0-9_]+)@[a-z0-9.-]+[a-z0-9]+)/ig, '$1@$3');
 }
diff --git a/app/javascript/mastodon/features/emoji/emoji_utils.js b/app/javascript/mastodon/features/emoji/emoji_utils.js
index 571907a509..be793526d0 100644
--- a/app/javascript/mastodon/features/emoji/emoji_utils.js
+++ b/app/javascript/mastodon/features/emoji/emoji_utils.js
@@ -73,7 +73,7 @@ const stringFromCodePoint = _String.fromCodePoint || function () {
 
 const _JSON = JSON;
 
-const COLONS_REGEX = /^(?:\:([^\:]+)\:)(?:\:skin-tone-(\d)\:)?$/;
+const COLONS_REGEX = /^(?::([^:]+):)(?::skin-tone-(\d):)?$/;
 const SKINS = [
   '1F3FA', '1F3FB', '1F3FC',
   '1F3FD', '1F3FE', '1F3FF',
diff --git a/app/javascript/mastodon/features/follow_recommendations/components/account.js b/app/javascript/mastodon/features/follow_recommendations/components/account.js
index daaa2f99ee..ddd0c8baab 100644
--- a/app/javascript/mastodon/features/follow_recommendations/components/account.js
+++ b/app/javascript/mastodon/features/follow_recommendations/components/account.js
@@ -27,7 +27,7 @@ const makeMapStateToProps = () => {
 };
 
 const getFirstSentence = str => {
-  const arr = str.split(/(([\.\?!]+\s)|[．。？！\n•])/);
+  const arr = str.split(/(([.?!]+\s)|[．。？！\n•])/);
 
   return arr[0];
 };
diff --git a/app/javascript/mastodon/features/picture_in_picture/components/footer.js b/app/javascript/mastodon/features/picture_in_picture/components/footer.js
index 3f59b891b8..0ee6d06c7f 100644
--- a/app/javascript/mastodon/features/picture_in_picture/components/footer.js
+++ b/app/javascript/mastodon/features/picture_in_picture/components/footer.js
@@ -184,7 +184,7 @@ class Footer extends ImmutablePureComponent {
         <IconButton className='status__action-bar-button' title={replyTitle} icon={status.get('in_reply_to_account_id') === status.getIn(['account', 'id']) ? 'reply' : replyIcon} onClick={this.handleReplyClick} counter={status.get('replies_count')} obfuscateCount />
         <IconButton className={classNames('status__action-bar-button', { reblogPrivate })} disabled={!publicStatus && !reblogPrivate}  active={status.get('reblogged')} title={reblogTitle} icon='retweet' onClick={this.handleReblogClick} counter={status.get('reblogs_count')} />
         <IconButton className='status__action-bar-button star-icon' animate active={status.get('favourited')} title={intl.formatMessage(messages.favourite)} icon='star' onClick={this.handleFavouriteClick} counter={status.get('favourites_count')} />
-        {withOpenButton && <IconButton className='status__action-bar-button' title={intl.formatMessage(messages.open)} icon='external-link' onClick={this.handleOpenClick} href={`/@${status.getIn(['account', 'acct'])}\/${status.get('id')}`} />}
+        {withOpenButton && <IconButton className='status__action-bar-button' title={intl.formatMessage(messages.open)} icon='external-link' onClick={this.handleOpenClick} href={`/@${status.getIn(['account', 'acct'])}/${status.get('id')}`} />}
       </div>
     );
   }
diff --git a/app/javascript/mastodon/features/status/components/detailed_status.js b/app/javascript/mastodon/features/status/components/detailed_status.js
index 116d9f6b27..064231ffe3 100644
--- a/app/javascript/mastodon/features/status/components/detailed_status.js
+++ b/app/javascript/mastodon/features/status/components/detailed_status.js
@@ -276,7 +276,7 @@ class DetailedStatus extends ImmutablePureComponent {
           {media}
 
           <div className='detailed-status__meta'>
-            <a className='detailed-status__datetime' href={`/@${status.getIn(['account', 'acct'])}\/${status.get('id')}`} target='_blank' rel='noopener noreferrer'>
+            <a className='detailed-status__datetime' href={`/@${status.getIn(['account', 'acct'])}/${status.get('id')}`} 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>{edited}{visibilityLink}{applicationLink}{reblogLink} · {favouriteLink}
           </div>
diff --git a/app/javascript/mastodon/features/ui/components/boost_modal.js b/app/javascript/mastodon/features/ui/components/boost_modal.js
index 087eadba2e..d6a6cea31e 100644
--- a/app/javascript/mastodon/features/ui/components/boost_modal.js
+++ b/app/javascript/mastodon/features/ui/components/boost_modal.js
@@ -98,7 +98,7 @@ class BoostModal extends ImmutablePureComponent {
         <div className='boost-modal__container'>
           <div className={classNames('status', `status-${status.get('visibility')}`, 'light')}>
             <div className='status__info'>
-              <a href={`/@${status.getIn(['account', 'acct'])}\/${status.get('id')}`} className='status__relative-time' target='_blank' rel='noopener noreferrer'>
+              <a href={`/@${status.getIn(['account', 'acct'])}/${status.get('id')}`} className='status__relative-time' target='_blank' rel='noopener noreferrer'>
                 <span className='status__visibility-icon'><Icon id={visibilityIcon.icon} title={visibilityIcon.text} /></span>
                 <RelativeTimestamp timestamp={status.get('created_at')} />
               </a>
diff --git a/config/webpack/shared.js b/config/webpack/shared.js
index 3447e711c1..78f660cfcd 100644
--- a/config/webpack/shared.js
+++ b/config/webpack/shared.js
@@ -55,7 +55,7 @@ module.exports = {
           chunks: 'all',
           minChunks: 2,
           minSize: 0,
-          test: /^(?!.*[\\\/]node_modules[\\\/]react-intl[\\\/]).+$/,
+          test: /^(?!.*[\\/]node_modules[\\/]react-intl[\\/]).+$/,
         },
       },
     },