diff --git a/core/modules/file/file.js b/core/modules/file/file.js
index 27e2775..1454a6e 100644
--- a/core/modules/file/file.js
+++ b/core/modules/file/file.js
@@ -94,7 +94,7 @@
     },
 
     triggerUploadButton: function triggerUploadButton(event) {
-      $(event.target).closest('.js-form-managed-file').find('.js-form-submit').trigger('mousedown');
+      $(event.target).closest('.js-form-managed-file').find('.managed-file-upload-button').trigger('mousedown');
     },
 
     disableFields: function disableFields(event) {
diff --git a/core/modules/file/src/Element/ManagedFile.php b/core/modules/file/src/Element/ManagedFile.php
index 45c8aa7..f457d96 100644
--- a/core/modules/file/src/Element/ManagedFile.php
+++ b/core/modules/file/src/Element/ManagedFile.php
@@ -239,7 +239,12 @@ public static function processManagedFile(&$element, FormStateInterface $form_st
       '#name' => $parents_prefix . '_upload_button',
       '#type' => 'submit',
       '#value' => t('Upload'),
-      '#attributes' => ['class' => ['js-hide']],
+      '#attributes' => [
+        'class' => [
+          'js-hide',
+          'managed-file-upload-button',
+        ]
+      ],
       '#validate' => [],
       '#submit' => ['file_managed_file_submit'],
       '#limit_validation_errors' => [$element['#parents']],