diff --git a/user_guide_src/source/changelogs/v4.2.0.rst b/user_guide_src/source/changelogs/v4.2.0.rst
index 32129c30c4eb..b314dd892794 100644
--- a/user_guide_src/source/changelogs/v4.2.0.rst
+++ b/user_guide_src/source/changelogs/v4.2.0.rst
@@ -22,6 +22,7 @@ BREAKING
 - The color code output by :ref:`CLI::color() <cli-library-color>` has been changed to fix a bug.
 - To prevent unexpected access from the web browser, if a controller is added to a cli route (``$routes->cli()``), all methods of that controller are no longer accessible via auto-routing.
 - There is a possible backward compatibility break for those users extending the History Collector and they should probably update ``History::setFiles()`` method.
+- The :php:func:`dot_array_search`'s unexpected behavior has been fixed. Now ``dot_array_search('foo.bar.baz', ['foo' => ['bar' => 23]])`` returns ``null``. The previous versions returned ``23``.
 
 Enhancements
 ************
diff --git a/user_guide_src/source/helpers/array_helper.rst b/user_guide_src/source/helpers/array_helper.rst
index 845ccccf39b4..cf9517925234 100644
--- a/user_guide_src/source/helpers/array_helper.rst
+++ b/user_guide_src/source/helpers/array_helper.rst
@@ -48,6 +48,9 @@ The following functions are available:
 
     .. literalinclude:: array_helper/005.php
 
+.. note:: Prior to v4.2.0, ``dot_array_search('foo.bar.baz', ['foo' => ['bar' => 23]])`` returned ``23``
+    due to a bug. v4.2.0 and later returns ``null``.
+
 ..  php:function:: array_deep_search($key, array $array)
 
     :param  mixed  $key: The target key