diff --git a/core/core.api.php b/core/core.api.php
index 2e247a8798..fb0cf0292d 100644
--- a/core/core.api.php
+++ b/core/core.api.php
@@ -2371,20 +2371,21 @@ function hook_validation_constraint_alter(array &$definitions) {
  * an array. Here are the details of its elements, all of which are optional:
  * - callback: The callback to invoke to handle the server side of the
  *   Ajax event. More information on callbacks is below in @ref sub_callback.
- * - wrapper: The HTML 'id' attribute of the area where the content returned by
- *   the callback should be placed. Note that callbacks have a choice of
- *   returning content or JavaScript commands; 'wrapper_selector' is used for content
- *   returns.
+ * - wrapper_selector: The CSS selector of the area where the content returned
+ *   by the callback should be placed. Note that callbacks have a choice of
+ *   returning content or JavaScript commands; 'wrapper_selector' is used for
+ *   content returns.
  * - method: The jQuery method for placing the new content (used with
- *   'wrapper_selector'). Valid options are 'replaceWith' (default), 'append', 'prepend',
- *   'before', 'after', or 'html'. See
+ *   'wrapper_selector'). Valid options are 'replaceWith' (default), 'append',
+ *   'prepend', 'before', 'after', or 'html'. See
  *   http://api.jquery.com/category/manipulation/ for more information on these
  *   methods.
  * - effect: The jQuery effect to use when placing the new HTML (used with
- *   'wrapper_selector'). Valid options are 'none' (default), 'slide', or 'fade'.
- * - speed: The effect speed to use (used with 'effect' and 'wrapper_selector'). Valid
- *   options are 'slow' (default), 'fast', or the number of milliseconds the
- *   effect should run.
+ *   'wrapper_selector'). Valid options are 'none' (default), 'slide', or
+ *   'fade'.
+ * - speed: The effect speed to use (used with 'effect' and 'wrapper_selector').
+ *   Valid options are 'slow' (default), 'fast', or the number of milliseconds
+ *   the effect should run.
  * - event: The JavaScript event to respond to. This is selected automatically
  *   for the type of form element; provide a value to override the default.
  * - prevent: A JavaScript event to prevent when the event is triggered. For
@@ -2449,8 +2450,8 @@ function hook_validation_constraint_alter(array &$definitions) {
  * invokes an arbitrary jQuery command.
  *
  * As noted above, status messages are prepended automatically if you use the
- * 'wrapper_selector' method and return HTML markup. This is not the case if you return
- * commands, but if you would like to show status messages, you can add
+ * 'wrapper_selector' method and return HTML markup. This is not the case if you
+ * return commands, but if you would like to show status messages, you can add
  * @code
  * array('#type' => 'status_messages')
  * @endcode
diff --git a/core/misc/ajax.es6.js b/core/misc/ajax.es6.js
index 70a17518af..26fa7ee377 100644
--- a/core/misc/ajax.es6.js
+++ b/core/misc/ajax.es6.js
@@ -7,8 +7,8 @@
  * then executed to make any changes that are necessary to the page.
  *
  * Drupal uses this file to enhance form elements with `#ajax['url']` and
- * `#ajax['wrapper_selector']` properties. If set, this file will automatically be
- * included to provide Ajax capabilities.
+ * `#ajax['wrapper_selector']` properties. If set, this file will automatically
+ * be included to provide Ajax capabilities.
  */
 
 (function($, window, Drupal, drupalSettings) {
@@ -360,8 +360,8 @@ function loadAjaxBehavior(base) {
    * then executed to make any changes that are necessary to the page.
    *
    * Drupal uses this file to enhance form elements with `#ajax['url']` and
-   * `#ajax['wrapper_selector']` properties. If set, this file will automatically be
-   * included to provide Ajax capabilities.
+   * `#ajax['wrapper_selector']` properties. If set, this file will
+   * automatically be included to provide Ajax capabilities.
    *
    * @constructor
    *