diff --git a/core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php b/core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php
index b3bfa9f..232783f 100644
--- a/core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php
+++ b/core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php
@@ -295,11 +295,12 @@ public function massageFormValues(array $values, array $form, FormStateInterface
       }
     }
 
-    // Remove stale reference to 'items' stored during upload.
+    // Update reference to 'items' stored during upload to take into account
+    // changes to values like 'alt' etc.
     // @see \Drupal\file\Plugin\Field\FieldWidget\FileWidget::submit()
     $field_name = $this->fieldDefinition->getName();
     $field_state = static::getWidgetState($form['#parents'], $field_name, $form_state);
-    unset($field_state['items']);
+    $field_state['items'] = $new_values;
     static::setWidgetState($form['#parents'], $field_name, $form_state, $field_state);
 
     return $new_values;