diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 1dfd9c762c46e..667f89c07e212 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -7,6 +7,8 @@
 /* global onEach, onEachLazy, removeClass */
 /* global switchTheme, useSystemTheme */
 
+"use strict";
+
 if (!String.prototype.startsWith) {
     String.prototype.startsWith = function(searchString, position) {
         position = position || 0;
@@ -292,15 +294,12 @@ function loadCss(cssFileName) {
 }
 
 (function() {
-    "use strict";
-
     function loadScript(url) {
         const script = document.createElement('script');
         script.src = url;
         document.head.append(script);
     }
 
-
     getSettingsButton().onclick = event => {
         event.preventDefault();
         loadScript(window.settingsJS);
diff --git a/src/librustdoc/html/static/js/scrape-examples.js b/src/librustdoc/html/static/js/scrape-examples.js
index 491b3950ae6eb..70fcef522129e 100644
--- a/src/librustdoc/html/static/js/scrape-examples.js
+++ b/src/librustdoc/html/static/js/scrape-examples.js
@@ -4,6 +4,8 @@
 /* eslint prefer-arrow-callback: "error" */
 /* global addClass, hasClass, removeClass, onEachLazy */
 
+"use strict";
+
 (function () {
     // Number of lines shown when code viewer is not expanded
     const MAX_LINES = 10;
diff --git a/src/librustdoc/html/static/js/search.js b/src/librustdoc/html/static/js/search.js
index 60ad431ba7a99..54ce2508c468d 100644
--- a/src/librustdoc/html/static/js/search.js
+++ b/src/librustdoc/html/static/js/search.js
@@ -5,7 +5,9 @@
 /* global addClass, getNakedUrl, getSettingValue, hasOwnPropertyRustdoc, initSearch, onEach */
 /* global onEachLazy, removeClass, searchState, browserSupportsHistoryApi */
 
-(function () {
+"use strict";
+
+(function() {
 // This mapping table should match the discriminants of
 // `rustdoc::formats::item_type::ItemType` type in Rust.
 const itemTypes = [
diff --git a/src/librustdoc/html/static/js/settings.js b/src/librustdoc/html/static/js/settings.js
index 43b24245ab2e8..119d4b07665a4 100644
--- a/src/librustdoc/html/static/js/settings.js
+++ b/src/librustdoc/html/static/js/settings.js
@@ -7,6 +7,8 @@
 /* global addClass, removeClass, onEach, onEachLazy, NOT_DISPLAYED_ID */
 /* global MAIN_ID, getVar, getSettingsButton, switchDisplayedElement, getNotDisplayedElem */
 
+"use strict";
+
 (function () {
     const isSettingsPage = window.location.pathname.endsWith("/settings.html");
 
diff --git a/src/librustdoc/html/static/js/source-script.js b/src/librustdoc/html/static/js/source-script.js
index 290bf40a8f577..f788d41d2ded4 100644
--- a/src/librustdoc/html/static/js/source-script.js
+++ b/src/librustdoc/html/static/js/source-script.js
@@ -9,7 +9,10 @@
 // Local js definitions:
 /* global addClass, getCurrentValue, hasClass, onEachLazy, removeClass, browserSupportsHistoryApi */
 /* global updateLocalStorage */
-(function () {
+
+"use strict";
+
+(function() {
 
 function getCurrentFilePath() {
     const parts = window.location.pathname.split("/");
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index 913fc278eb387..052731e99aed2 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -3,6 +3,8 @@
 /* eslint prefer-const: "error" */
 /* eslint prefer-arrow-callback: "error" */
 
+"use strict";
+
 const darkThemes = ["dark", "ayu"];
 window.currentTheme = document.getElementById("themeStyle");
 window.mainTheme = document.getElementById("mainThemeStyle");