diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 5a4f3d1..2574550 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1075,9 +1075,6 @@ function template_preprocess_datetime(&$variables) {
  *     displaying messages of that specific type.
  */
 function template_preprocess_status_messages(&$variables) {
-  if (isset($variables['message_list'])) {
-    return;
-  }
   $variables['message_list'] = drupal_get_messages($variables['display']);
   $variables['status_headings'] = array(
     'status' => t('Status message'),
@@ -2512,6 +2509,12 @@ function drupal_common_theme() {
       'template' => 'datetime',
     ),
     'status_messages' => array(
+      'variables' => array('display' => NULL),
+      'template' => 'status-messages',
+    ),
+    // @TODO changes this to status_messages once the messages are gone from
+    // template_preprocess_page
+    'status_messages_block' => array(
       'variables' => array('status_headings' => array(), 'message_list' => NULL, 'display' => NULL),
       'template' => 'status-messages',
     ),
diff --git a/core/modules/system/src/Plugin/Block/SystemPageMessagesBlock.php b/core/modules/system/src/Plugin/Block/SystemPageMessagesBlock.php
index 154bf07..1d2b8c6 100644
--- a/core/modules/system/src/Plugin/Block/SystemPageMessagesBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemPageMessagesBlock.php
@@ -72,11 +72,13 @@ public function defaultConfiguration() {
    */
   public function build() {
 
-    $build['message_list'] = array(
-      '#theme' => 'status_messages',
+    $build['messages'] = array(
+      // @TODO change this to status_messages once the messages are gone from
+      // template_preprocess_page
+      '#theme' => 'status_messages_block',
       '#pre_render' => array(array($this, 'getMessages')),
     );
-    $build['message_list']['#status_headings'] = array(
+    $build['messages']['#status_headings'] = array(
       'status' => t('Status message'),
       'error' => t('Error message'),
       'warning' => t('Warning message'),
@@ -92,7 +94,7 @@ public function build() {
    * @return mixed
    */
   public function getMessages($element) {
-    $element['#markup'] = drupal_get_messages();
+    $element['#message_list'] = drupal_get_messages();
     return $element;
   }
 
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index f703fd1..f20a637 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -1108,6 +1108,10 @@ function system_preprocess_block(&$variables) {
       }
       break;
 
+    case 'system_page_messages_block':
+      $variables['messages'] = $variables['content']['messages'];
+      break;
+
     case 'system_powered_by_block':
       $variables['attributes']['role'] = 'complementary';
       break;
diff --git a/core/modules/system/templates/block--system-page-messages-block.html.twig b/core/modules/system/templates/block--system-page-messages-block.html.twig
index a93c908..86b4b52 100644
--- a/core/modules/system/templates/block--system-page-messages-block.html.twig
+++ b/core/modules/system/templates/block--system-page-messages-block.html.twig
@@ -14,10 +14,7 @@
  * user agents will better describe this landmark.
  *
  * Available variables:
- * - message_list: List of messages to be displayed, grouped by type.
- * - status_headings: List of all status types.
- * - display: (optional) May have a value of 'status' or 'error' when only
- *   displaying messages of that specific type.
+ * - messages: Status and error messages. Should be displayed prominently.
  *
  * @see template_preprocess_status_messages()
  *
@@ -25,26 +22,5 @@
  */
 #}
 {% block content %}
-  {% for type, messages in message_list %}
-    <div class="messages messages--{{ type }}" role="contentinfo" aria-label="{{ status_headings[type] }}">
-      {% if type == 'error' %}
-        <div role="alert">
-      {% endif %}
-        {% if status_headings[type] %}
-          <h2 class="visually-hidden">{{ status_headings[type] }}</h2>
-        {% endif %}
-        {% if messages|length > 1 %}
-          <ul class="messages__list">
-          {% for message in messages %}
-            <li class="messages__item">{{ message }}</li>
-          {% endfor %}
-          </ul>
-        {% else %}
-          {{ messages.0 }}
-        {% endif %}
-        {% if type == 'error' %}
-        </div>
-      {% endif %}
-    </div>
-  {% endfor %}
+  {{ messages }}
 {% endblock %}
diff --git a/core/themes/bartik/templates/block--system-page-messages.html.twig b/core/themes/bartik/templates/block--system-page-messages.html.twig
index 8e2e08b..80e59b6 100644
--- a/core/themes/bartik/templates/block--system-page-messages.html.twig
+++ b/core/themes/bartik/templates/block--system-page-messages.html.twig
@@ -14,10 +14,7 @@
  * user agents will better describe this landmark.
  *
  * Available variables:
- * - message_list: List of messages to be displayed, grouped by type.
- * - status_headings: List of all status types.
- * - display: (optional) May have a value of 'status' or 'error' when only
- *   displaying messages of that specific type.
+ * - messages: Status and error messages. Should be displayed prominently.
  *
  * @see template_preprocess_status_messages()
  *
@@ -25,28 +22,9 @@
  */
 #}
 {% block content %}
-  <div id="messages"><div class="section clearfix">
-    {% for type, messages in message_list %}
-      <div class="messages messages--{{ type }}" role="contentinfo" aria-label="{{ status_headings[type] }}">
-        {% if type == 'error' %}
-          <div role="alert">
-        {% endif %}
-          {% if status_headings[type] %}
-            <h2 class="visually-hidden">{{ status_headings[type] }}</h2>
-          {% endif %}
-          {% if messages|length > 1 %}
-            <ul class="messages__list">
-            {% for message in messages %}
-              <li class="messages__item">{{ message }}</li>
-            {% endfor %}
-            </ul>
-          {% else %}
-            {{ messages.0 }}
-          {% endif %}
-        {% if type == 'error' %}
-          </div>
-        {% endif %}
-      </div>
-    {% endfor %}
-  </div></div> <!-- /.section, /#messages -->
+  {% if messages %}
+    <div id="messages"><div class="section clearfix">
+      {{ messages }}
+    </div></div> <!-- /.section, /#messages -->
+  {% endif %}
 {% endblock %}