diff --git a/core/modules/file/file.js b/core/modules/file/file.js
index 8f0c9db..640aec8 100644
--- a/core/modules/file/file.js
+++ b/core/modules/file/file.js
@@ -68,12 +68,12 @@
     attach: function (context) {
       var $context = $(context);
       $context.find('.js-form-submit').on('mousedown', Drupal.file.disableFields);
-      $context.find('.form-managed-file .js-form-submit').on('mousedown', Drupal.file.progressBar);
+      $context.find('.js-form-managed-file .form-submit').on('mousedown', Drupal.file.progressBar);
     },
     detach: function (context) {
       var $context = $(context);
       $context.find('.js-form-submit').off('mousedown', Drupal.file.disableFields);
-      $context.find('.form-managed-file .js-form-submit').off('mousedown', Drupal.file.progressBar);
+      $context.find('.js-form-managed-file .js-form-submit').off('mousedown', Drupal.file.progressBar);
     }
   };
 
@@ -82,10 +82,10 @@
    */
   Drupal.behaviors.filePreviewLinks = {
     attach: function (context) {
-      $(context).find('div.form-managed-file .file a, .file-widget .file a').on('click', Drupal.file.openInNewWindow);
+      $(context).find('div.js-form-managed-file .file a, .file-widget .file a').on('click', Drupal.file.openInNewWindow);
     },
     detach: function (context) {
-      $(context).find('div.form-managed-file .file a, .file-widget .file a').off('click', Drupal.file.openInNewWindow);
+      $(context).find('div.js-form-managed-file .file a, .file-widget .file a').off('click', Drupal.file.openInNewWindow);
     }
   };
 
@@ -117,7 +117,7 @@
             '%filename': this.value.replace('C:\\fakepath\\', ''),
             '%extensions': extensionPattern.replace(/\|/g, ', ')
           });
-          $(this).closest('div.form-managed-file').prepend('<div class="messages messages--error file-upload-js-error" aria-live="polite">' + error + '</div>');
+          $(this).closest('div.js-form-managed-file').prepend('<div class="messages messages--error file-upload-js-error" aria-live="polite">' + error + '</div>');
           this.value = '';
           // Cancel all other change event handlers.
           event.stopImmediatePropagation();
@@ -128,7 +128,7 @@
      * Trigger the upload_button mouse event to auto-upload as a managed file.
      */
     triggerUploadButton: function (event) {
-      $(event.target).closest('.form-managed-file').find('.js-form-submit').trigger('mousedown');
+      $(event.target).closest('.js-form-managed-file').find('.js-form-submit').trigger('mousedown');
     },
     /**
      * Prevent file uploads when using buttons not intended to upload.
@@ -143,8 +143,8 @@
 
       // Check if we're working with an "Upload" button.
       var $enabledFields = [];
-      if ($clickedButton.closest('div.form-managed-file').length > 0) {
-        $enabledFields = $clickedButton.closest('div.form-managed-file').find('input.form-file');
+      if ($clickedButton.closest('div.js-form-managed-file').length > 0) {
+        $enabledFields = $clickedButton.closest('div.js-form-managed-file').find('input.js-form-file');
       }
 
       // Temporarily disable upload fields other than the one we're currently
@@ -155,7 +155,7 @@
       // behaviors) are executed before any timeout functions are called, so we
       // don't have to worry about the fields being re-enabled too soon.
       // @todo If the previous sentence is true, why not set the timeout to 0?
-      var $fieldsToTemporarilyDisable = $('div.form-managed-file input.form-file').not($enabledFields).not(':disabled');
+      var $fieldsToTemporarilyDisable = $('div.js-form-managed-file input.js-form-file').not($enabledFields).not(':disabled');
       $fieldsToTemporarilyDisable.prop('disabled', true);
       setTimeout(function () {
         $fieldsToTemporarilyDisable.prop('disabled', false);
@@ -166,7 +166,7 @@
      */
     progressBar: function (event) {
       var $clickedButton = $(this);
-      var $progressId = $clickedButton.closest('div.form-managed-file').find('input.file-progress');
+      var $progressId = $clickedButton.closest('div.js-form-managed-file').find('input.file-progress');
       if ($progressId.length) {
         var originalName = $progressId.attr('name');
 
@@ -180,7 +180,7 @@
       }
       // Show the progress bar if the upload takes longer than half a second.
       setTimeout(function () {
-        $clickedButton.closest('div.form-managed-file').find('div.ajax-progress-bar').slideDown();
+        $clickedButton.closest('div.js-form-managed-file').find('div.ajax-progress-bar').slideDown();
       }, 500);
     },
     /**