diff --git c/core/modules/content_translation/src/ContentTranslationHandler.php w/core/modules/content_translation/src/ContentTranslationHandler.php
index d2643be..31b3bba 100644
--- c/core/modules/content_translation/src/ContentTranslationHandler.php
+++ w/core/modules/content_translation/src/ContentTranslationHandler.php
@@ -603,20 +603,18 @@ public function entityFormSourceChange($form, FormStateInterface $form_state) {
    *
    * Takes care of entity deletion.
    */
-  function entityFormDelete($form, FormStateInterface $form_state) {
+  function entityFormDelete(&$form, FormStateInterface $form_state) {
     $entity = $form_state->getFormObject()->getEntity();
     $is_translation = $entity->language()->getId() != $entity->getUntranslated()->language()->getId();
     $languages = [];
     foreach ($entity->getTranslationLanguages() as $language) {
       array_push($languages, t('@language', array('@language' => $language->getName())));
     }
-    $languages = join($languages, ', ');
     if (count($entity->getTranslationLanguages()) > 1 && !$is_translation) {
-      drupal_set_message(t('This will delete the following translations: @languages',
-        array(
-          '%label' => $entity->label(),
-          '@languages'   => $languages,
-        )), 'warning');
+      $form['languages'] = array(
+        '#theme' => 'item_list',
+        '#items' => $languages,
+      );
     }
   }