diff --git a/user_guide_src/source/changelogs/v4.2.0.rst b/user_guide_src/source/changelogs/v4.2.0.rst
index 93c81004522c..c5f25f1b8396 100644
--- a/user_guide_src/source/changelogs/v4.2.0.rst
+++ b/user_guide_src/source/changelogs/v4.2.0.rst
@@ -16,7 +16,7 @@ BREAKING
 - The ``CodeIgniter\CodeIgniter`` class has a new property ``$context`` and it must have the correct context at runtime. So the following files have been changed:
     - ``public/index.php``
     - ``spark``
-- The ``system/bootstrap.php`` no longer returns a ``CodeIgniter`` instance, and does not load ``.env`` file.
+- The ``system/bootstrap.php`` file has been modified to easily implement `Preloading <https://www.php.net/manual/en/opcache.preloading.php>`_. Returning a ``CodeIgniter`` instance and loading ``.env`` file have been moved to ``index.php`` and ``spark``.
 - The method signature of ``CodeIgniter\CLI\CommandRunner::_remap()`` has been changed to fix a bug.
 - The ``CodeIgniter\Autoloader\Autoloader::initialize()`` has changed the behavior to fix a bug. It used to use Composer classmap only when ``$modules->discoverInComposer`` is true. Now it always uses the Composer classmap if Composer is available.
 - The color code output by :ref:`CLI::color() <cli-library-color>` has been changed to fix a bug.
diff --git a/user_guide_src/source/installation/upgrade_420.rst b/user_guide_src/source/installation/upgrade_420.rst
index dc77c28ed85e..4e39cb3aee51 100644
--- a/user_guide_src/source/installation/upgrade_420.rst
+++ b/user_guide_src/source/installation/upgrade_420.rst
@@ -24,7 +24,7 @@ The following files received significant changes and
 Breaking Changes
 ****************
 
-- The ``system/bootstrap.php`` file no longer returns a ``CodeIgniter`` instance, and does not load the ``.env`` file (now handled in ``index.php`` and ``spark``). If you have code that expects these behaviors it will no longer work and must be modified.
+- The ``system/bootstrap.php`` file no longer returns a ``CodeIgniter`` instance, and does not load the ``.env`` file (now handled in ``index.php`` and ``spark``). If you have code that expects these behaviors it will no longer work and must be modified. This has been changed to make `Preloading <https://www.php.net/manual/en/opcache.preloading.php>`_ easier to implement.
 
 Breaking Enhancements
 *********************