diff --git a/core/includes/common.inc b/core/includes/common.inc
index 26680c1538d9841c250dd6e7d2657efae5a4e866..91aa48570af6fb605084a3a649b58394221e6b94 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -856,9 +856,9 @@ function drupal_process_states(&$elements) {
  * foreach ($regions as $region) {
  *   drupal_attach_tabledrag('my-module-table', array(
  *     'action' => 'order',
- *     'relationship' => sibling',
+ *     'relationship' => 'sibling',
  *     'group' => 'my-elements-weight',
- *     'subgroup' => my-elements-weight-' . $region,
+ *     'subgroup' => 'my-elements-weight-' . $region,
  *   ));
  * }
  * @endcode