diff --git a/core/tests/Drupal/KernelTests/Core/Theme/ConfirmClassyCopiesTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ConfirmClassyCopiesTest.php
index 24caa8f983..a6a0d2a96b 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/ConfirmClassyCopiesTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/ConfirmClassyCopiesTest.php
@@ -306,7 +306,6 @@ public function providerTestClassyCopies() {
             'rdf-metadata.html.twig',
             'help-section.html.twig',
             'progress-bar.html.twig',
-            'textarea.html.twig',
             'radios.html.twig',
             'item-list.html.twig',
             'aggregator-feed.html.twig',
diff --git a/core/themes/claro/claro.theme b/core/themes/claro/claro.theme
index 9ac7404832..5d735acb6b 100644
--- a/core/themes/claro/claro.theme
+++ b/core/themes/claro/claro.theme
@@ -748,15 +748,6 @@ function claro_preprocess_input(&$variables) {
   }
 }
 
-/**
- * Implements template_preprocess_HOOK() for textarea.
- */
-function claro_preprocess_textarea(&$variables) {
-  $variables['attributes']['class'][] = 'form-element';
-  $variables['attributes']['class'][] = 'form-element--type-textarea';
-  $variables['attributes']['class'][] = 'form-element--api-textarea';
-}
-
 /**
  * Implements template_preprocess_HOOK() for select.
  */
diff --git a/core/themes/claro/templates/classy/form/textarea.html.twig b/core/themes/claro/templates/form/textarea.html.twig
similarity index 88%
rename from core/themes/claro/templates/classy/form/textarea.html.twig
rename to core/themes/claro/templates/form/textarea.html.twig
index 99e1bde090..ab7b972853 100644
--- a/core/themes/claro/templates/classy/form/textarea.html.twig
+++ b/core/themes/claro/templates/form/textarea.html.twig
@@ -18,6 +18,9 @@
     'form-textarea',
     resizable ? 'resize-' ~ resizable,
     required ? 'required',
+    'form-element',
+    'form-element--type-textarea',
+    'form-element--api-textarea',
   ]
 %}
 <div{{ wrapper_attributes.addClass('form-textarea-wrapper') }}>