diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 0a74451..1ee3e9e 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1788,9 +1788,9 @@ function template_preprocess_item_list(&$variables) {
     $attributes = array();
     // If the item value is an array, then it is a render array.
     if (is_array($item)) {
-      // List items support attributes via the 'attributes' property.
-      if (isset($item['attributes']) && is_array($item['attributes'])) {
-        $attributes = $item['attributes'];
+      // List items support attributes via the '#wrapper_attributes' property.
+      if (isset($item['#wrapper_attributes']) && is_array($item['#wrapper_attributes'])) {
+        $attributes = $item['#wrapper_attributes'];
       }
       // Determine whether there are any child elements in the item that are not
       // fully-specified render arrays. If there are any, then the child
@@ -1821,13 +1821,12 @@ function template_preprocess_item_list(&$variables) {
         }
       }
     }
-    else {
-      // Turn the item into an array if it wasn't one already.
-      $item = array('value' => $item);
-    }
+
+    // Store item value for Twig.
+    $item = array('value' => $item);
 
     // Store item attributes for Twig.
-    $item['attributes'] = new Attribute($attributes);
+    $item['attributes'] =  new Attribute($attributes);
   }
 }
 
diff --git a/core/modules/system/templates/item-list.html.twig b/core/modules/system/templates/item-list.html.twig
index 2936224..1586b78 100644
--- a/core/modules/system/templates/item-list.html.twig
+++ b/core/modules/system/templates/item-list.html.twig
@@ -30,7 +30,7 @@
       <ol{{ attributes }}>
     {%- endif %}
       {%- for item in items -%}
-        <li {{ item.attributes }}>{{ item.value }}</li>
+        <li{{ item.attributes }}>{{ item.value }}</li>
       {%- endfor -%}
     {%- if list_type == 'ul' -%}
       </ul>