diff --git a/src/components/ButtonLink/ButtonLink.js b/src/components/ButtonLink/ButtonLink.js
index 50eb0119..4abbd0ff 100644
--- a/src/components/ButtonLink/ButtonLink.js
+++ b/src/components/ButtonLink/ButtonLink.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Link from 'gatsby-link';
 import React from 'react';
 import {colors, media} from 'theme';
diff --git a/src/components/ButtonLink/index.js b/src/components/ButtonLink/index.js
index b17f0bf1..f4ed7b7a 100644
--- a/src/components/ButtonLink/index.js
+++ b/src/components/ButtonLink/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import ButtonLink from './ButtonLink';
 
 export default ButtonLink;
diff --git a/src/components/CodeEditor/CodeEditor.js b/src/components/CodeEditor/CodeEditor.js
index a843de82..f4f187f3 100644
--- a/src/components/CodeEditor/CodeEditor.js
+++ b/src/components/CodeEditor/CodeEditor.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React, {Component} from 'react';
 import ReactDOM from 'react-dom';
 import Remarkable from 'remarkable';
diff --git a/src/components/CodeEditor/index.js b/src/components/CodeEditor/index.js
index 74799777..4cd1787d 100644
--- a/src/components/CodeEditor/index.js
+++ b/src/components/CodeEditor/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import CodeEditor from './CodeEditor';
 
 export default CodeEditor;
diff --git a/src/components/Container/Container.js b/src/components/Container/Container.js
index 7a458faf..8ed280c5 100644
--- a/src/components/Container/Container.js
+++ b/src/components/Container/Container.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import React from 'react';
 
 import {media} from 'theme';
diff --git a/src/components/Container/index.js b/src/components/Container/index.js
index 6a609558..6270e9c6 100644
--- a/src/components/Container/index.js
+++ b/src/components/Container/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Container from './Container';
 
 export default Container;
diff --git a/src/components/ErrorDecoder/ErrorDecoder.js b/src/components/ErrorDecoder/ErrorDecoder.js
index 51f2d8c3..db01876f 100644
--- a/src/components/ErrorDecoder/ErrorDecoder.js
+++ b/src/components/ErrorDecoder/ErrorDecoder.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import React from 'react';
 
 import type {Node} from 'react';
diff --git a/src/components/ErrorDecoder/index.js b/src/components/ErrorDecoder/index.js
index 68931622..a3762d42 100644
--- a/src/components/ErrorDecoder/index.js
+++ b/src/components/ErrorDecoder/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import ErrorDecoder from './ErrorDecoder';
 
 export default ErrorDecoder;
diff --git a/src/components/Flex/Flex.js b/src/components/Flex/Flex.js
index 8784aa79..4d7e74ae 100644
--- a/src/components/Flex/Flex.js
+++ b/src/components/Flex/Flex.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import {createElement} from 'glamor/react';
 
 import type {Node} from 'react';
diff --git a/src/components/Flex/index.js b/src/components/Flex/index.js
index 1ec92e45..47818263 100644
--- a/src/components/Flex/index.js
+++ b/src/components/Flex/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Flex from './Flex';
 
 export default Flex;
diff --git a/src/components/Header/Header.js b/src/components/Header/Header.js
index 1314d725..39422d95 100644
--- a/src/components/Header/Header.js
+++ b/src/components/Header/Header.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import React from 'react';
 import {colors, fonts} from 'theme';
 
diff --git a/src/components/Header/index.js b/src/components/Header/index.js
index 57114581..239c1152 100644
--- a/src/components/Header/index.js
+++ b/src/components/Header/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Header from './Header';
 
 export default Header;
diff --git a/src/components/LayoutFooter/ExternalFooterLink.js b/src/components/LayoutFooter/ExternalFooterLink.js
index 1d77ed6c..db061f4a 100644
--- a/src/components/LayoutFooter/ExternalFooterLink.js
+++ b/src/components/LayoutFooter/ExternalFooterLink.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import React from 'react';
 import {colors} from 'theme';
 import ExternalLinkSvg from 'templates/components/ExternalLinkSvg';
diff --git a/src/components/LayoutFooter/Footer.js b/src/components/LayoutFooter/Footer.js
index 8a518fd8..f3b81885 100644
--- a/src/components/LayoutFooter/Footer.js
+++ b/src/components/LayoutFooter/Footer.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import ExternalFooterLink from './ExternalFooterLink';
 import FooterLink from './FooterLink';
diff --git a/src/components/LayoutFooter/FooterLink.js b/src/components/LayoutFooter/FooterLink.js
index 1e54b75c..70eae5ad 100644
--- a/src/components/LayoutFooter/FooterLink.js
+++ b/src/components/LayoutFooter/FooterLink.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Link from 'gatsby-link';
 import React from 'react';
 import {colors} from 'theme';
diff --git a/src/components/LayoutFooter/FooterNav.js b/src/components/LayoutFooter/FooterNav.js
index 914d8a6b..d94c7db6 100644
--- a/src/components/LayoutFooter/FooterNav.js
+++ b/src/components/LayoutFooter/FooterNav.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import React from 'react';
 import {media} from 'theme';
 
diff --git a/src/components/LayoutFooter/index.js b/src/components/LayoutFooter/index.js
index 42db340a..1ffbe907 100644
--- a/src/components/LayoutFooter/index.js
+++ b/src/components/LayoutFooter/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Footer from './Footer';
 
 export default Footer;
diff --git a/src/components/LayoutHeader/Header.js b/src/components/LayoutHeader/Header.js
index 09464456..f5ec82d3 100644
--- a/src/components/LayoutHeader/Header.js
+++ b/src/components/LayoutHeader/Header.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import HeaderLink from './HeaderLink';
 import Link from 'gatsby-link';
diff --git a/src/components/LayoutHeader/HeaderLink.js b/src/components/LayoutHeader/HeaderLink.js
index 7ef61f09..e7314d6d 100644
--- a/src/components/LayoutHeader/HeaderLink.js
+++ b/src/components/LayoutHeader/HeaderLink.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Link from 'gatsby-link';
 import React from 'react';
 import {colors, media} from 'theme';
diff --git a/src/components/LayoutHeader/SearchSvg.js b/src/components/LayoutHeader/SearchSvg.js
index af88d5a6..e3604b32 100644
--- a/src/components/LayoutHeader/SearchSvg.js
+++ b/src/components/LayoutHeader/SearchSvg.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React from 'react';
 
 const SearchSvg = () => (
diff --git a/src/components/LayoutHeader/index.js b/src/components/LayoutHeader/index.js
index 57114581..239c1152 100644
--- a/src/components/LayoutHeader/index.js
+++ b/src/components/LayoutHeader/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Header from './Header';
 
 export default Header;
diff --git a/src/components/MarkdownHeader/MarkdownHeader.js b/src/components/MarkdownHeader/MarkdownHeader.js
index de11ea61..b638d833 100644
--- a/src/components/MarkdownHeader/MarkdownHeader.js
+++ b/src/components/MarkdownHeader/MarkdownHeader.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Flex from 'components/Flex';
 import React from 'react';
 import {colors, fonts, media} from 'theme';
diff --git a/src/components/MarkdownHeader/index.js b/src/components/MarkdownHeader/index.js
index c338ea60..9455e3c6 100644
--- a/src/components/MarkdownHeader/index.js
+++ b/src/components/MarkdownHeader/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import MarkdownHeader from './MarkdownHeader';
 
 export default MarkdownHeader;
diff --git a/src/components/MarkdownPage/MarkdownPage.js b/src/components/MarkdownPage/MarkdownPage.js
index b43b8e09..634bed23 100644
--- a/src/components/MarkdownPage/MarkdownPage.js
+++ b/src/components/MarkdownPage/MarkdownPage.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import Flex from 'components/Flex';
 import MarkdownHeader from 'components/MarkdownHeader';
diff --git a/src/components/MarkdownPage/index.js b/src/components/MarkdownPage/index.js
index 589ca08e..83f7c3fb 100644
--- a/src/components/MarkdownPage/index.js
+++ b/src/components/MarkdownPage/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import MarkdownPage from './MarkdownPage';
 
 export default MarkdownPage;
diff --git a/src/components/StickyResponsiveSidebar/StickyResponsiveSidebar.js b/src/components/StickyResponsiveSidebar/StickyResponsiveSidebar.js
index d58a24d0..fc5d074d 100644
--- a/src/components/StickyResponsiveSidebar/StickyResponsiveSidebar.js
+++ b/src/components/StickyResponsiveSidebar/StickyResponsiveSidebar.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import React, {Component} from 'react';
 import Sidebar from 'templates/components/Sidebar';
diff --git a/src/components/StickyResponsiveSidebar/index.js b/src/components/StickyResponsiveSidebar/index.js
index 4e10be51..7c0650c6 100644
--- a/src/components/StickyResponsiveSidebar/index.js
+++ b/src/components/StickyResponsiveSidebar/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import StickyResponsiveSidebar from './StickyResponsiveSidebar';
 
 export default StickyResponsiveSidebar;
diff --git a/src/components/TitleAndMetaTags/TitleAndMetaTags.js b/src/components/TitleAndMetaTags/TitleAndMetaTags.js
index 5d985060..37dc325b 100644
--- a/src/components/TitleAndMetaTags/TitleAndMetaTags.js
+++ b/src/components/TitleAndMetaTags/TitleAndMetaTags.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Helmet from 'react-helmet';
 import React from 'react';
 
diff --git a/src/components/TitleAndMetaTags/index.js b/src/components/TitleAndMetaTags/index.js
index e8bea5ed..f85ab40b 100644
--- a/src/components/TitleAndMetaTags/index.js
+++ b/src/components/TitleAndMetaTags/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import TitleAndMetaTags from './TitleAndMetaTags';
 
 export default TitleAndMetaTags;
diff --git a/src/html.js b/src/html.js
index 4a113917..474aae64 100644
--- a/src/html.js
+++ b/src/html.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React, {Component} from 'react';
 
 let stylesStr;
diff --git a/src/layouts/index.js b/src/layouts/index.js
index 3630653b..4da990bd 100644
--- a/src/layouts/index.js
+++ b/src/layouts/index.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 // Polyfills for IE
 import 'array-from';
 import 'string.prototype.includes';
diff --git a/src/pages/404.js b/src/pages/404.js
index 5ad0aebb..35bef3ae 100644
--- a/src/pages/404.js
+++ b/src/pages/404.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import Header from 'components/Header';
 import TitleAndMetaTags from 'components/TitleAndMetaTags';
diff --git a/src/pages/acknowledgements.html.js b/src/pages/acknowledgements.html.js
index 962f6e2f..5252e13b 100644
--- a/src/pages/acknowledgements.html.js
+++ b/src/pages/acknowledgements.html.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import Header from 'components/Header';
 import TitleAndMetaTags from 'components/TitleAndMetaTags';
diff --git a/src/pages/blog/all.html.js b/src/pages/blog/all.html.js
index b7ba40bd..e28c8c09 100644
--- a/src/pages/blog/all.html.js
+++ b/src/pages/blog/all.html.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Link from 'gatsby-link';
 import Container from 'components/Container';
 import Header from 'components/Header';
diff --git a/src/pages/docs/error-decoder.html.js b/src/pages/docs/error-decoder.html.js
index d1b0e451..4f97caf3 100644
--- a/src/pages/docs/error-decoder.html.js
+++ b/src/pages/docs/error-decoder.html.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import ErrorDecoder from 'components/ErrorDecoder';
 import Flex from 'components/Flex';
diff --git a/src/pages/index.js b/src/pages/index.js
index ed85bbc3..514b064e 100644
--- a/src/pages/index.js
+++ b/src/pages/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import ButtonLink from 'components/ButtonLink';
 import Container from 'components/Container';
 import Flex from 'components/Flex';
diff --git a/src/pages/jsx-compiler.html.js b/src/pages/jsx-compiler.html.js
index 836c09d9..1cb4be48 100644
--- a/src/pages/jsx-compiler.html.js
+++ b/src/pages/jsx-compiler.html.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import Header from 'components/Header';
 import React from 'react';
diff --git a/src/prism-styles.js b/src/prism-styles.js
index 665ef8ab..736bbe3b 100644
--- a/src/prism-styles.js
+++ b/src/prism-styles.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import {css} from 'glamor';
 import {colors} from 'theme';
 
diff --git a/src/site-constants.js b/src/site-constants.js
index 69880117..3d1412c8 100644
--- a/src/site-constants.js
+++ b/src/site-constants.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 // NOTE: We can't just use `location.toString()` because when we are rendering
 // the SSR part in node.js we won't have a proper location.
 const urlRoot = 'https://reactjs.org';
diff --git a/src/templates/blog.js b/src/templates/blog.js
index e520f718..22255eb6 100644
--- a/src/templates/blog.js
+++ b/src/templates/blog.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import PropTypes from 'prop-types';
 import React from 'react';
 import MarkdownPage from 'components/MarkdownPage';
diff --git a/src/templates/codepen-example.js b/src/templates/codepen-example.js
index c4f7945b..890f6db2 100644
--- a/src/templates/codepen-example.js
+++ b/src/templates/codepen-example.js
@@ -1,5 +1,3 @@
-'use strict';
-
 import React, {Component} from 'react';
 import Container from 'components/Container';
 import {colors} from 'theme';
diff --git a/src/templates/community.js b/src/templates/community.js
index 72f7a222..15bab696 100644
--- a/src/templates/community.js
+++ b/src/templates/community.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import MarkdownPage from 'components/MarkdownPage';
 import PropTypes from 'prop-types';
 import React from 'react';
diff --git a/src/templates/components/ChevronSvg/index.js b/src/templates/components/ChevronSvg/index.js
index 1e2e77e0..f6c8fe53 100644
--- a/src/templates/components/ChevronSvg/index.js
+++ b/src/templates/components/ChevronSvg/index.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import React from 'react';
 
 type Props = {
diff --git a/src/templates/components/ExternalLinkSvg/index.js b/src/templates/components/ExternalLinkSvg/index.js
index 0ff4d79d..08a8f592 100644
--- a/src/templates/components/ExternalLinkSvg/index.js
+++ b/src/templates/components/ExternalLinkSvg/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React from 'react';
 
 const ExternalLinkSvg = ({cssProps = {}}: {cssProps: Object}) => (
diff --git a/src/templates/components/MetaTitle/index.js b/src/templates/components/MetaTitle/index.js
index 8bfd1425..ada617c6 100644
--- a/src/templates/components/MetaTitle/index.js
+++ b/src/templates/components/MetaTitle/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React from 'react';
 import {colors} from 'theme';
 
diff --git a/src/templates/components/NavigationFooter/NavigationFooter.js b/src/templates/components/NavigationFooter/NavigationFooter.js
index 1c1a0f25..d29c16c6 100644
--- a/src/templates/components/NavigationFooter/NavigationFooter.js
+++ b/src/templates/components/NavigationFooter/NavigationFooter.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Container from 'components/Container';
 import Flex from 'components/Flex';
 import Link from 'gatsby-link';
diff --git a/src/templates/components/NavigationFooter/index.js b/src/templates/components/NavigationFooter/index.js
index 6b9cd4b7..bf848789 100644
--- a/src/templates/components/NavigationFooter/index.js
+++ b/src/templates/components/NavigationFooter/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import NavigationFooter from './NavigationFooter';
 
 export default NavigationFooter;
diff --git a/src/templates/components/Sidebar/ScrollSyncSection.js b/src/templates/components/Sidebar/ScrollSyncSection.js
index a1a717b6..62e2b88d 100644
--- a/src/templates/components/Sidebar/ScrollSyncSection.js
+++ b/src/templates/components/Sidebar/ScrollSyncSection.js
@@ -7,8 +7,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React, {Component} from 'react';
 import Section from './Section';
 
diff --git a/src/templates/components/Sidebar/Section.js b/src/templates/components/Sidebar/Section.js
index 98e049fa..bf6db263 100644
--- a/src/templates/components/Sidebar/Section.js
+++ b/src/templates/components/Sidebar/Section.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React from 'react';
 import {colors, media} from 'theme';
 import isItemActive from 'utils/isItemActive';
diff --git a/src/templates/components/Sidebar/Sidebar.js b/src/templates/components/Sidebar/Sidebar.js
index 0ed8c5af..b4199931 100644
--- a/src/templates/components/Sidebar/Sidebar.js
+++ b/src/templates/components/Sidebar/Sidebar.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import React, {Component} from 'react';
 import Flex from 'components/Flex';
 import Section from './Section';
diff --git a/src/templates/components/Sidebar/index.js b/src/templates/components/Sidebar/index.js
index 642dd09f..e1d4ef6f 100644
--- a/src/templates/components/Sidebar/index.js
+++ b/src/templates/components/Sidebar/index.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import Sidebar from './Sidebar';
 
 export default Sidebar;
diff --git a/src/templates/docs.js b/src/templates/docs.js
index b087d6d0..5d55b689 100644
--- a/src/templates/docs.js
+++ b/src/templates/docs.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import MarkdownPage from 'components/MarkdownPage';
 import PropTypes from 'prop-types';
 import React from 'react';
diff --git a/src/templates/tutorial.js b/src/templates/tutorial.js
index 33efed97..bf65ca13 100644
--- a/src/templates/tutorial.js
+++ b/src/templates/tutorial.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import MarkdownPage from 'components/MarkdownPage';
 import PropTypes from 'prop-types';
 import React from 'react';
diff --git a/src/theme.js b/src/theme.js
index ab304ef4..cc8504af 100644
--- a/src/theme.js
+++ b/src/theme.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 /**
  * Theme contains variables shared by styles of multiple components.
  */
diff --git a/src/utils/createLink.js b/src/utils/createLink.js
index 9f6def70..450acc45 100644
--- a/src/utils/createLink.js
+++ b/src/utils/createLink.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import Link from 'gatsby-link';
 import React from 'react';
 import ExternalLinkSvg from 'templates/components/ExternalLinkSvg';
diff --git a/src/utils/createOgUrl.js b/src/utils/createOgUrl.js
index b6c3ee82..0fafad59 100644
--- a/src/utils/createOgUrl.js
+++ b/src/utils/createOgUrl.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import {urlRoot} from 'site-constants';
 
 export default (slug: string): string | null =>
diff --git a/src/utils/findSectionForPath.js b/src/utils/findSectionForPath.js
index cf02e67a..eedffc0a 100644
--- a/src/utils/findSectionForPath.js
+++ b/src/utils/findSectionForPath.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import slugify from './slugify';
 
 /**
diff --git a/src/utils/isItemActive.js b/src/utils/isItemActive.js
index fd766aea..754db4b8 100644
--- a/src/utils/isItemActive.js
+++ b/src/utils/isItemActive.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import slugify from 'utils/slugify';
 
 const toAnchor = (href: string = ''): string => {
diff --git a/src/utils/loadScript.js b/src/utils/loadScript.js
index aae19658..83fa80a6 100644
--- a/src/utils/loadScript.js
+++ b/src/utils/loadScript.js
@@ -7,8 +7,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 export default url =>
   new Promise((resolve, reject) =>
     document.head.appendChild(
diff --git a/src/utils/mountCodeExample.js b/src/utils/mountCodeExample.js
index a7ebece8..41c35eef 100644
--- a/src/utils/mountCodeExample.js
+++ b/src/utils/mountCodeExample.js
@@ -4,8 +4,6 @@
  * @emails react-core
  */
 
-'use strict';
-
 import CodeEditor from '../components/CodeEditor';
 import React from 'react';
 import ReactDOM from 'react-dom';
diff --git a/src/utils/sectionList.js b/src/utils/sectionList.js
index f2ef5a39..a52f28b9 100644
--- a/src/utils/sectionList.js
+++ b/src/utils/sectionList.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 // $FlowExpectedError
 import navCommunity from '../../content/community/nav.yml';
 // $FlowExpectedError
diff --git a/src/utils/slugify.js b/src/utils/slugify.js
index 7ca42ad0..cf2ef384 100644
--- a/src/utils/slugify.js
+++ b/src/utils/slugify.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import slugify from 'slugify';
 
 export default (string: string, directory?: string): string => {
diff --git a/src/utils/toCommaSeparatedList.js b/src/utils/toCommaSeparatedList.js
index 319a5031..e70da06f 100644
--- a/src/utils/toCommaSeparatedList.js
+++ b/src/utils/toCommaSeparatedList.js
@@ -5,8 +5,6 @@
  * @flow
  */
 
-'use strict';
-
 import React from 'react';
 
 import type {Node} from 'react';