diff -u b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
--- b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
@@ -18,8 +18,8 @@
  *   id = "uuid",
  *   label = @Translation("UUID"),
  *   description = @Translation("An entity field containing a UUID."),
- *   no_ui = TRUE
- *   default_formatter = "basic_string",
+ *   no_ui = TRUE,
+ *   default_formatter = "basic_string"
  * )
  */
 class UuidItem extends StringItem {