diff -u b/core/includes/form.inc b/core/includes/form.inc
--- b/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -1597,9 +1597,8 @@
  *
  * Adds a column of radio buttons or checkboxes for each row of a table.
  *
- * @param $variables
- *   An associative array containing:
- *   - element: An associative array containing the properties and children of
+ * @param $element
+ *     An associative array containing the properties and children of
  *     the tableselect element. Properties used: #header, #options, #empty,
  *     and #js_select. The #options property is an array of selection options;
  *     each array element of #options is an array of properties. These