diff --git a/build/media_source/system/js/core.es6.js b/build/media_source/system/js/core.es6.js
index 9707f1a0a9d8d..445bf492ee422 100644
--- a/build/media_source/system/js/core.es6.js
+++ b/build/media_source/system/js/core.es6.js
@@ -109,7 +109,7 @@ window.Joomla.Modal = window.Joomla.Modal || {
       newDestination = {};
     }
 
-    [].slice.call(Object.keys(source)).forEach((key) => {
+    Object.keys(source).forEach((key) => {
       newDestination[key] = source[key];
     });
 
@@ -155,10 +155,9 @@ window.Joomla.Modal = window.Joomla.Modal || {
   Joomla.loadOptions = (options) => {
     // Load form the script container
     if (!options) {
-      const elements = [].slice.call(document.querySelectorAll('.joomla-script-options.new'));
       let counter = 0;
 
-      elements.forEach((element) => {
+      document.querySelectorAll('.joomla-script-options.new').forEach((element) => {
         const str = element.text || element.textContent;
         const option = JSON.parse(str);
 
@@ -180,7 +179,7 @@ window.Joomla.Modal = window.Joomla.Modal || {
       Joomla.optionsStorage = options || {};
     } else if (options) {
       // Merge with existing
-      [].slice.call(Object.keys(options)).forEach((key) => {
+      Object.keys(options).forEach((key) => {
         /**
          * If both existing and new options are objects, merge them with Joomla.extend().
          * But test for new option being null, as null is an object, but we want to allow
@@ -241,7 +240,7 @@ window.Joomla.Modal = window.Joomla.Modal || {
      * @returns {Joomla.Text}
      */
     load: (object) => {
-      [].slice.call(Object.keys(object)).forEach((key) => {
+      Object.keys(object).forEach((key) => {
         Joomla.Text.strings[key.toUpperCase()] = object[key];
       });
 
@@ -513,10 +512,8 @@ window.Joomla.Modal = window.Joomla.Modal || {
       return;
     }
 
-    const elements = [].slice.call(document.getElementsByTagName('input'));
-
-    elements.forEach((element) => {
-      if (element.type === 'hidden' && element.value === '1' && element.name.length === 32) {
+    document.querySelectorAll('input[type="hidden"]').forEach((element) => {
+      if (element.value === '1' && element.name.length === 32) {
         element.name = newToken;
       }
     });
@@ -596,7 +593,7 @@ window.Joomla.Modal = window.Joomla.Modal || {
 
       // Custom headers
       if (newOptions.headers) {
-        [].slice.call(Object.keys(newOptions.headers)).forEach((key) => {
+        Object.keys(newOptions.headers).forEach((key) => {
           // Allow request without Content-Type
           // eslint-disable-next-line no-empty
           if (key === 'Content-Type' && newOptions.headers['Content-Type'] === 'false') {
diff --git a/build/media_source/system/js/fields/joomla-field-permissions.w-c.es6.js b/build/media_source/system/js/fields/joomla-field-permissions.w-c.es6.js
index 4a65e499b1c3c..ed881acd8aae5 100644
--- a/build/media_source/system/js/fields/joomla-field-permissions.w-c.es6.js
+++ b/build/media_source/system/js/fields/joomla-field-permissions.w-c.es6.js
@@ -32,7 +32,7 @@ window.customElements.define('joomla-field-permissions', class extends HTMLEleme
    * Lifecycle
    */
   connectedCallback() {
-    this.buttons = [].slice.call(document.querySelectorAll(`[${this.buttonDataSelector}]`));
+    this.buttons = document.querySelectorAll(`[${this.buttonDataSelector}]`);
     if (this.buttons) {
       this.buttons.forEach((button) => {
         button.addEventListener('change', this.onDropdownChange);
diff --git a/build/media_source/system/js/fields/joomla-field-simple-color.w-c.es6.js b/build/media_source/system/js/fields/joomla-field-simple-color.w-c.es6.js
index dea9a903b953c..48c1c6362b35c 100644
--- a/build/media_source/system/js/fields/joomla-field-simple-color.w-c.es6.js
+++ b/build/media_source/system/js/fields/joomla-field-simple-color.w-c.es6.js
@@ -215,7 +215,7 @@
         throw new Error('Simple color field requires a select element');
       }
 
-      this.options = [].slice.call(this.select.querySelectorAll('option'));
+      this.options = this.select.querySelectorAll('option');
 
       this.select.classList.add('hidden');
 
diff --git a/build/media_source/system/js/fields/passwordstrength.es6.js b/build/media_source/system/js/fields/passwordstrength.es6.js
index 1ca7f259f6bec..17db26e1a1440 100644
--- a/build/media_source/system/js/fields/passwordstrength.es6.js
+++ b/build/media_source/system/js/fields/passwordstrength.es6.js
@@ -121,7 +121,7 @@ class PasswordStrength {
   };
 
   document.addEventListener('DOMContentLoaded', () => {
-    const fields = [].slice.call(document.querySelectorAll('.js-password-strength'));
+    const fields = document.querySelectorAll('.js-password-strength');
 
     // Loop  through the fields
     fields.forEach((field, index) => {
@@ -155,9 +155,7 @@ class PasswordStrength {
       }
 
       // Add a listener for input data change
-      field.addEventListener('keyup', ({ target }) => {
-        getMeter(target);
-      });
+      field.addEventListener('keyup', ({ target }) => getMeter(target));
     });
 
     // Set a handler for the validation script
diff --git a/build/media_source/system/js/fields/select-colour.es6.js b/build/media_source/system/js/fields/select-colour.es6.js
index c44d100454c5c..22174b2094d0e 100644
--- a/build/media_source/system/js/fields/select-colour.es6.js
+++ b/build/media_source/system/js/fields/select-colour.es6.js
@@ -19,9 +19,7 @@
   };
 
   const updateSelectboxColour = () => {
-    const colourSelects = [].slice.call(document.querySelectorAll('.form-select-color-state'));
-
-    colourSelects.forEach((colourSelect) => {
+    document.querySelectorAll('.form-select-color-state').forEach((colourSelect) => {
       const value = parseInt(colourSelect.value, 10);
 
       // Add class on page load
diff --git a/build/media_source/system/js/fields/validate.es6.js b/build/media_source/system/js/fields/validate.es6.js
index 5412dc52bd15f..13b47cbdbab3d 100644
--- a/build/media_source/system/js/fields/validate.es6.js
+++ b/build/media_source/system/js/fields/validate.es6.js
@@ -37,9 +37,7 @@ class JFormValidator {
     });
 
     // Attach all forms with a class 'form-validate'
-    const forms = [].slice.call(document.querySelectorAll('form'));
-
-    forms.forEach((form) => {
+    document.querySelectorAll('form').forEach((form) => {
       if (form.classList.contains('form-validate')) {
         this.attachToForm(form);
       }
@@ -74,8 +72,7 @@ class JFormValidator {
       }
     }
 
-    element.classList.remove('form-control-danger');
-    element.classList.remove('invalid');
+    element.classList.remove('form-control-danger', 'invalid');
     element.classList.add('form-control-success');
     element.parentNode.classList.remove('has-danger');
     element.parentNode.classList.add('has-success');
@@ -97,10 +94,8 @@ class JFormValidator {
     // Get a label
     const label = element.form.querySelector(`label[for="${element.id}"]`);
 
-    element.classList.remove('form-control-success');
-    element.classList.remove('valid');
-    element.classList.add('form-control-danger');
-    element.classList.add('invalid');
+    element.classList.remove('form-control-success', 'valid');
+    element.classList.add('form-control-danger', 'invalid');
     element.parentNode.classList.remove('has-success');
     element.parentNode.classList.add('has-danger');
     element.setAttribute('aria-invalid', 'true');
@@ -145,18 +140,13 @@ class JFormValidator {
       message = label.querySelector('span.form-control-feedback');
     }
 
-    element.classList.remove('form-control-danger');
-    element.classList.remove('form-control-success');
-    element.classList.remove('invalid');
+    element.classList.remove('form-control-danger', 'form-control-success', 'remove');
     element.classList.add('valid');
-    element.parentNode.classList.remove('has-danger');
-    element.parentNode.classList.remove('has-success');
+    element.parentNode.classList.remove('has-danger', 'has-success');
 
     // Remove message
-    if (message) {
-      if (label) {
-        label.removeChild(message);
-      }
+    if (message && label) {
+      label.removeChild(message);
     }
 
     // Restore Label
@@ -256,7 +246,7 @@ class JFormValidator {
     if (form.nodeName === 'FORM') {
       fields = [].slice.call(form.elements);
     } else {
-      fields = [].slice.call(form.querySelectorAll('input, textarea, select, button, fieldset'));
+      fields = form.querySelectorAll('input, textarea, select, button, fieldset');
     }
     fields.forEach((field) => {
       if (this.validate(field) === false) {
@@ -294,7 +284,7 @@ class JFormValidator {
     if (form.nodeName === 'FORM') {
       elements = [].slice.call(form.elements);
     } else {
-      elements = [].slice.call(form.querySelectorAll('input, textarea, select, button, fieldset'));
+      elements = form.querySelectorAll('input, textarea, select, button, fieldset');
     }
 
     // Iterate through the form object and attach the validate method to all input fields.
diff --git a/build/media_source/system/js/highlight.es6.js b/build/media_source/system/js/highlight.es6.js
index 24ea4f61f55f5..65e6ec77b8e34 100644
--- a/build/media_source/system/js/highlight.es6.js
+++ b/build/media_source/system/js/highlight.es6.js
@@ -29,9 +29,7 @@ if (Joomla.getOptions && typeof Joomla.getOptions === 'function' && Joomla.getOp
         const instance = new Mark(element);
 
         // Loop through the terms
-        options.highLight.forEach((term) => {
-          instance.mark(term, options);
-        });
+        options.highLight.forEach((term) => instance.mark(term, options));
       }
     } else {
       const start = document.querySelector(`#${options.start}`);
diff --git a/build/media_source/system/js/inlinehelp.es6.js b/build/media_source/system/js/inlinehelp.es6.js
index 6236b9581f02c..3df8df51bb8e7 100644
--- a/build/media_source/system/js/inlinehelp.es6.js
+++ b/build/media_source/system/js/inlinehelp.es6.js
@@ -9,49 +9,47 @@
  * @param {String} toggleClass The class name of the DIVs to toggle display for
  */
 Joomla.toggleInlineHelp = (toggleClass) => {
-  [].slice.call(document.querySelectorAll(`div.${toggleClass}`))
-    .forEach((elDiv) => {
-      // Toggle the visibility of the node by toggling the 'd-none' Bootstrap class.
-      elDiv.classList.toggle('d-none');
-      // The ID of the description whose visibility is toggled.
-      const myId = elDiv.id;
-      // The ID of the control described by this node (same ID, minus the '-desc' suffix).
-      const controlId = myId ? myId.substr(0, myId.length - 5) : null;
-      // Get the control described by this node.
-      const elControl = controlId ? document.getElementById(controlId) : null;
-      // Is this node hidden?
-      const isHidden = elDiv.classList.contains('d-none');
+  document.querySelectorAll(`div.${toggleClass}`).forEach((elDiv) => {
+    // Toggle the visibility of the node by toggling the 'd-none' Bootstrap class.
+    elDiv.classList.toggle('d-none');
+    // The ID of the description whose visibility is toggled.
+    const myId = elDiv.id;
+    // The ID of the control described by this node (same ID, minus the '-desc' suffix).
+    const controlId = myId ? myId.substr(0, myId.length - 5) : null;
+    // Get the control described by this node.
+    const elControl = controlId ? document.getElementById(controlId) : null;
+    // Is this node hidden?
+    const isHidden = elDiv.classList.contains('d-none');
 
-      // If we do not have a control we will exit early
-      if (!controlId || !elControl) {
-        return;
-      }
+    // If we do not have a control we will exit early
+    if (!controlId || !elControl) {
+      return;
+    }
 
-      // Unset the aria-describedby attribute in the control when the description is hidden and vice–versa.
-      if (isHidden && elControl.hasAttribute('aria-describedby')) {
-        elControl.removeAttribute('aria-describedby');
-      } else if (!isHidden) {
-        elControl.setAttribute('aria-describedby', myId);
-      }
-    });
+    // Unset the aria-describedby attribute in the control when the description is hidden and vice–versa.
+    if (isHidden && elControl.hasAttribute('aria-describedby')) {
+      elControl.removeAttribute('aria-describedby');
+    } else if (!isHidden) {
+      elControl.setAttribute('aria-describedby', myId);
+    }
+  });
 };
 
 // Initialisation. Clicking on anything with the button-inlinehelp class will toggle the inline help.
-[].slice.call(document.querySelectorAll('.button-inlinehelp'))
-  .forEach((elToggler) => {
-    // The class of the DIVs to toggle visibility on is defined by the data-class attribute of the click target.
-    const toggleClass = elToggler.dataset.class ?? 'hide-aware-inline-help';
-    const collection = document.getElementsByClassName(toggleClass);
+document.querySelectorAll('.button-inlinehelp').forEach((elToggler) => {
+  // The class of the DIVs to toggle visibility on is defined by the data-class attribute of the click target.
+  const toggleClass = elToggler.dataset.class ?? 'hide-aware-inline-help';
+  const collection = document.getElementsByClassName(toggleClass);
 
-    // no description => hide inlinehelp button
-    if (collection.length === 0) {
-      elToggler.classList.add('d-none');
-      return;
-    }
+  // no description => hide inlinehelp button
+  if (collection.length === 0) {
+    elToggler.classList.add('d-none');
+    return;
+  }
 
-    // Add the click handler.
-    elToggler.addEventListener('click', (event) => {
-      event.preventDefault();
-      Joomla.toggleInlineHelp(toggleClass);
-    });
+  // Add the click handler.
+  elToggler.addEventListener('click', (event) => {
+    event.preventDefault();
+    Joomla.toggleInlineHelp(toggleClass);
   });
+});
diff --git a/build/media_source/system/js/messages.es6.js b/build/media_source/system/js/messages.es6.js
index 40c80a533789c..9a6545940882d 100644
--- a/build/media_source/system/js/messages.es6.js
+++ b/build/media_source/system/js/messages.es6.js
@@ -53,7 +53,7 @@ Joomla.renderMessages = (messages, selector, keepOld, timeout) => {
     Joomla.removeMessages(messageContainer);
   }
 
-  [].slice.call(Object.keys(messages)).forEach((type) => {
+  Object.keys(messages).forEach((type) => {
     let alertClass = type;
 
     // Array of messages of this type
@@ -107,12 +107,7 @@ Joomla.renderMessages = (messages, selector, keepOld, timeout) => {
  */
 Joomla.removeMessages = (container) => {
   const messageContainer = getMessageContainer(container);
-  const alerts = [].slice.call(messageContainer.querySelectorAll('joomla-alert'));
-  if (alerts.length) {
-    alerts.forEach((alert) => {
-      alert.close();
-    });
-  }
+  messageContainer.querySelectorAll('joomla-alert').forEach((alert) => alert.close());
 };
 
 document.addEventListener('DOMContentLoaded', () => {
diff --git a/build/media_source/system/js/searchtools.es6.js b/build/media_source/system/js/searchtools.es6.js
index ab5ad08a52c0b..0bbf7e90b1103 100644
--- a/build/media_source/system/js/searchtools.es6.js
+++ b/build/media_source/system/js/searchtools.es6.js
@@ -110,7 +110,7 @@ Joomla = window.Joomla || {};
       this.clearButton = document.querySelector(this.options.clearBtnSelector);
 
       // Ordering
-      this.orderCols = Array.prototype.slice.call(document.querySelectorAll(`${this.options.formSelector} ${this.options.orderColumnSelector}`));
+      this.orderCols = document.querySelectorAll(`${this.options.formSelector} ${this.options.orderColumnSelector}`);
       this.orderField = document.querySelector(`${this.options.formSelector} ${this.options.orderFieldSelector}`);
 
       // Limit
@@ -375,17 +375,17 @@ Joomla = window.Joomla || {};
     // eslint-disable-next-line consistent-return
     getFilterFields() {
       if (this.mainContainer) {
-        return Array.prototype.slice.call(this.mainContainer.querySelectorAll('select,input'));
+        return this.mainContainer.querySelectorAll('select,input');
       }
       if (this.filterContainer) {
-        return Array.prototype.slice.call(this.filterContainer.querySelectorAll('select,input'));
+        return this.filterContainer.querySelectorAll('select,input');
       }
 
       return [];
     }
 
     getListFields() {
-      return Array.prototype.slice.call(this.listContainer.querySelectorAll('select'));
+      return this.listContainer.querySelectorAll('select');
     }
 
     // Common container functions
diff --git a/build/media_source/system/js/showon.es6.js b/build/media_source/system/js/showon.es6.js
index d675c60e6ac9f..03035eb381a2c 100644
--- a/build/media_source/system/js/showon.es6.js
+++ b/build/media_source/system/js/showon.es6.js
@@ -22,7 +22,7 @@ class Showon {
       // }
     };
 
-    this.showonFields = [].slice.call(this.container.querySelectorAll('[data-showon]'));
+    this.showonFields = this.container.querySelectorAll('[data-showon]');
     // Populate the fields data
     if (this.showonFields.length) {
       // @todo refactor this, dry
@@ -38,7 +38,7 @@ class Showon {
         let localFields;
 
         if (showonData.length) {
-          localFields = [].slice.call(self.container.querySelectorAll(`[name="${showonData[0].field}"], [name="${showonData[0].field}[]"]`));
+          localFields = self.container.querySelectorAll(`[name="${showonData[0].field}"], [name="${showonData[0].field}[]"]`);
 
           if (!this.fields[showonData[0].field]) {
             this.fields[showonData[0].field] = {
@@ -64,7 +64,7 @@ class Showon {
                 return;
               }
 
-              localFields = [].slice.call(self.container.querySelectorAll(`[name="${value.field}"], [name="${value.field}[]"]`));
+              localFields = self.container.querySelectorAll(`[name="${value.field}"], [name="${value.field}[]"]`);
 
               if (!this.fields[showonData[0].field]) {
                 this.fields[showonData[0].field] = {
@@ -260,7 +260,7 @@ const getMatchedParents = ($child, selector) => {
 document.addEventListener('joomla:updated', ({ target }) => {
   // Check is it subform, then wee need to fix some "showon" config
   if (target.classList.contains('subform-repeatable-group')) {
-    const elements = [].slice.call(target.querySelectorAll('[data-showon]'));
+    const elements = target.querySelectorAll('[data-showon]');
 
     if (elements.length) {
       const search = [];
diff --git a/build/media_source/system/js/table-columns.es6.js b/build/media_source/system/js/table-columns.es6.js
index d6e72c2efa6b0..023e149381cb4 100644
--- a/build/media_source/system/js/table-columns.es6.js
+++ b/build/media_source/system/js/table-columns.es6.js
@@ -8,7 +8,7 @@ class TableColumns {
     this.storageKey = `joomla-tablecolumns-${this.tableName}`;
 
     this.$headers = [].slice.call($table.querySelector('thead tr').children);
-    this.$rows = [].slice.call($table.querySelectorAll('tbody tr'));
+    this.$rows = $table.querySelectorAll('tbody tr');
     this.listOfHidden = [];
 
     // Load previous state
diff --git a/build/media_source/templates/site/cassiopeia/js/mod_menu/menu-metismenu.es6.js b/build/media_source/templates/site/cassiopeia/js/mod_menu/menu-metismenu.es6.js
index ede6c6096b70a..1122a96994316 100644
--- a/build/media_source/templates/site/cassiopeia/js/mod_menu/menu-metismenu.es6.js
+++ b/build/media_source/templates/site/cassiopeia/js/mod_menu/menu-metismenu.es6.js
@@ -7,9 +7,7 @@
  */
 
 document.addEventListener('DOMContentLoaded', () => {
-  const allMenus = document.querySelectorAll('ul.mod-menu_dropdown-metismenu');
-
-  allMenus.forEach((menu) => {
+  document.querySelectorAll('ul.mod-menu_dropdown-metismenu').forEach((menu) => {
     // eslint-disable-next-line no-new, no-undef
     const mm = new MetisMenu(menu, {
       triggerElement: 'button.mm-toggler',
diff --git a/build/media_source/templates/site/cassiopeia/js/template.es5.js b/build/media_source/templates/site/cassiopeia/js/template.es5.js
deleted file mode 100644
index fa6a218e3a6a2..0000000000000
--- a/build/media_source/templates/site/cassiopeia/js/template.es5.js
+++ /dev/null
@@ -1,74 +0,0 @@
-/**
- * @package     Joomla.Site
- * @subpackage  Templates.Cassiopeia
- * @copyright   (C) 2017 Open Source Matters, Inc. <https://www.joomla.org>
- * @license     GNU General Public License version 2 or later; see LICENSE.txt
- * @since       4.0.0
- */
-
-Joomla = window.Joomla || {};
-
-(function(Joomla, document) {
-  'use strict';
-
-  function initTemplate(event) {
-    var target = event && event.target ? event.target : document;
-
-    /**
-     * Prevent clicks on buttons within a disabled fieldset
-     */
-    var fieldsets = target.querySelectorAll('fieldset.btn-group');
-    for (var i = 0; i < fieldsets.length; i++) {
-      var self = fieldsets[i];
-      if (self.getAttribute('disabled') ===  true) {
-        self.style.pointerEvents = 'none';
-        var btns = self.querySelectorAll('.btn');
-        for (var ib = 0; ib < btns.length; ib++) {
-          btns[ib].classList.add('disabled');
-        }
-      }
-    }
-  }
-
-  document.addEventListener('DOMContentLoaded', function (event) {
-    initTemplate(event);
-
-    /**
-     * Back to top
-     */
-    var backToTop = document.getElementById('back-top');
-
-    if (backToTop) {
-
-      function checkScrollPos() {
-        if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
-          backToTop.classList.add('visible');
-        } else {
-          backToTop.classList.remove('visible')
-        }
-      }
-
-      checkScrollPos();
-
-      window.onscroll = function() {
-        checkScrollPos();
-      };
-
-      backToTop.addEventListener('click', function(event) {
-        event.preventDefault();
-        window.scrollTo(0, 0);
-      });
-    }
-
-    [].slice.call(document.head.querySelectorAll('link[rel="lazy-stylesheet"]'))
-      .forEach(function($link){
-        $link.rel = "stylesheet";
-      });
-  });
-
-  /**
-   * Initialize when a part of the page was updated
-   */
-  document.addEventListener('joomla:updated', initTemplate);
-
-})(Joomla, document);
diff --git a/build/media_source/templates/site/cassiopeia/js/template.es6.js b/build/media_source/templates/site/cassiopeia/js/template.es6.js
new file mode 100644
index 0000000000000..bbdbbd6d2269d
--- /dev/null
+++ b/build/media_source/templates/site/cassiopeia/js/template.es6.js
@@ -0,0 +1,64 @@
+/**
+ * @package     Joomla.Site
+ * @subpackage  Templates.Cassiopeia
+ * @copyright   (C) 2017 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ * @since       4.0.0
+ */
+
+Joomla = window.Joomla || {};
+
+((Joomla, document) => {
+  'use strict';
+
+  function initTemplate(event) {
+    const target = event && event.target ? event.target : document;
+
+    /**
+     * Prevent clicks on buttons within a disabled fieldset
+     */
+    target.querySelectorAll('fieldset.btn-group').forEach((fieldset) => {
+      if (fieldset.getAttribute('disabled') === true) {
+        fieldset.style.pointerEvents = 'none';
+        fieldset.querySelectorAll('.btn').forEach((btn) => btn.classList.add('disabled'));
+      }
+    });
+  }
+
+  document.addEventListener('DOMContentLoaded', (event) => {
+    initTemplate(event);
+
+    /**
+     * Back to top
+     */
+    const backToTop = document.getElementById('back-top');
+
+    function checkScrollPos() {
+      if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
+        backToTop.classList.add('visible');
+      } else {
+        backToTop.classList.remove('visible');
+      }
+    }
+
+    if (backToTop) {
+      checkScrollPos();
+
+      window.addEventListener('scroll', checkScrollPos);
+
+      backToTop.addEventListener('click', (ev) => {
+        ev.preventDefault();
+        window.scrollTo(0, 0);
+      });
+    }
+
+    document.head.querySelectorAll('link[rel="lazy-stylesheet"]').forEach(($link) => {
+      $link.rel = 'stylesheet';
+    });
+  });
+
+  /**
+   * Initialize when a part of the page was updated
+   */
+  document.addEventListener('joomla:updated', initTemplate);
+})(Joomla, document);
diff --git a/build/media_source/vendor/bootstrap/js/alert.es6.js b/build/media_source/vendor/bootstrap/js/alert.es6.js
index 131f87a63cbe7..a5b9aae1d6793 100644
--- a/build/media_source/vendor/bootstrap/js/alert.es6.js
+++ b/build/media_source/vendor/bootstrap/js/alert.es6.js
@@ -9,8 +9,7 @@ if (Joomla && Joomla.getOptions) {
   // Initialise the elements
   if (alerts && alerts.length) {
     alerts.forEach((selector) => {
-      Array.from(document.querySelectorAll(selector))
-        .map((el) => new window.bootstrap.Alert(el));
+      document.querySelectorAll(selector).forEach((el) => new window.bootstrap.Alert(el));
     });
   }
 }
diff --git a/build/media_source/vendor/bootstrap/js/button.es6.js b/build/media_source/vendor/bootstrap/js/button.es6.js
index d75088aace4cc..3d94067277404 100644
--- a/build/media_source/vendor/bootstrap/js/button.es6.js
+++ b/build/media_source/vendor/bootstrap/js/button.es6.js
@@ -9,8 +9,7 @@ if (Joomla && Joomla.getOptions) {
   // Initialise the elements
   if (buttons && buttons.length) {
     buttons.forEach((selector) => {
-      Array.from(document.querySelectorAll(selector))
-        .map((el) => new window.bootstrap.Button(el));
+      document.querySelectorAll(selector).forEach((el) => new window.bootstrap.Button(el));
     });
   }
 }
diff --git a/build/media_source/vendor/bootstrap/js/modal.es6.js b/build/media_source/vendor/bootstrap/js/modal.es6.js
index 1fbf524dff9f4..35839b7d833c9 100644
--- a/build/media_source/vendor/bootstrap/js/modal.es6.js
+++ b/build/media_source/vendor/bootstrap/js/modal.es6.js
@@ -150,8 +150,7 @@ if (Joomla && Joomla.getOptions) {
         focus: opt.focus ? opt.focus : true,
       };
 
-      Array.from(document.querySelectorAll(modal))
-        .map((modalEl) => Joomla.initialiseModal(modalEl, options));
+      document.querySelectorAll(modal).forEach((modalEl) => Joomla.initialiseModal(modalEl, options));
     });
   }
 }
diff --git a/build/media_source/vendor/bootstrap/js/tab.es6.js b/build/media_source/vendor/bootstrap/js/tab.es6.js
index 4b93724a0c499..fc0be169e1c26 100644
--- a/build/media_source/vendor/bootstrap/js/tab.es6.js
+++ b/build/media_source/vendor/bootstrap/js/tab.es6.js
@@ -54,8 +54,7 @@ Joomla.initialiseTabs = (el, options) => {
       }
     }
   } else {
-    Array.from(document.querySelectorAll(`${el} a`))
-      .map((tab) => new window.bootstrap.Tab(tab, options));
+    document.querySelectorAll(`${el} a`).forEach((tab) => new window.bootstrap.Tab(tab, options));
   }
 };