diff --git a/core/includes/form.inc b/core/includes/form.inc
index 694fb41..1cce3c7 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -361,7 +361,6 @@ function template_preprocess_form(&$variables) {
function template_preprocess_textarea(&$variables) {
$element = $variables['element'];
Element::setAttributes($element, array('id', 'name', 'rows', 'cols', 'placeholder'));
- Element\RenderElement::setAttributes($element, array('form-textarea'));
$variables['wrapper_attributes'] = new Attribute();
$variables['attributes'] = new Attribute($element['#attributes']);
$variables['value'] = String::checkPlain($element['#value']);
diff --git a/core/modules/system/src/Tests/Theme/TableTest.php b/core/modules/system/src/Tests/Theme/TableTest.php
index 88aa25f..1440c92 100644
--- a/core/modules/system/src/Tests/Theme/TableTest.php
+++ b/core/modules/system/src/Tests/Theme/TableTest.php
@@ -91,6 +91,11 @@ function testThemeTableWithEmptyMessage() {
'#rows' => array(),
'#empty' => 'Empty row.',
);
+
+ // Enable the Classy theme.
+ \Drupal::service('theme_handler')->install(['classy']);
+ $this->config('system.theme')->set('default', 'classy')->save();
+
$this->render($table);
$this->removeWhiteSpace();
$this->assertRaw(' ', 'Table header found.');
diff --git a/core/modules/system/templates/table.html.twig b/core/modules/system/templates/table.html.twig
index 3d0252e..0ecc34c 100644
--- a/core/modules/system/templates/table.html.twig
+++ b/core/modules/system/templates/table.html.twig
@@ -62,12 +62,7 @@
Header 1 Header 2
{% for cell in header %}
- {%
- set cell_classes = [
- cell.active_table_sort ? 'active',
- ]
- %}
- <{{ cell.tag }}{{ cell.attributes.addClass(cell_classes) }}>
+ <{{ cell.tag }}{{ cell.attributes }}>
{{- cell.content -}}
{{ cell.tag }}>
{% endfor %}
@@ -78,12 +73,7 @@
{% if rows %}