diff --git a/core/lib/Drupal/Core/Render/Element/Button.php b/core/lib/Drupal/Core/Render/Element/Button.php
index ac34e42..a646157 100644
--- a/core/lib/Drupal/Core/Render/Element/Button.php
+++ b/core/lib/Drupal/Core/Render/Element/Button.php
@@ -76,7 +76,6 @@ public static function preRenderButton($element) {
     if (!empty($element['#button_type'])) {
       $element['#attributes']['class'][] = 'button--' . $element['#button_type'];
     }
-    // @todo Various JavaScript depends on this button class.
     $element['#attributes']['class'][] = 'js-form-submit';
     $element['#attributes']['class'][] = 'form-submit';
 
diff --git a/core/lib/Drupal/Core/Render/Element/ImageButton.php b/core/lib/Drupal/Core/Render/Element/ImageButton.php
index 5517792..4ee39a6 100644
--- a/core/lib/Drupal/Core/Render/Element/ImageButton.php
+++ b/core/lib/Drupal/Core/Render/Element/ImageButton.php
@@ -85,7 +85,7 @@ public static function preRenderButton($element) {
     if (!empty($element['#button_type'])) {
       $element['#attributes']['class'][] = 'image-button--' . $element['#button_type'];
     }
-    // @todo Various JavaScript depends on this button class.
+    $element['#attributes']['class'][] = 'js-form-submit';
     $element['#attributes']['class'][] = 'form-submit';
 
     if (!empty($element['#attributes']['disabled'])) {