diff --git a/system/Config/Factories.php b/system/Config/Factories.php
index 4bf2428ab0e0..ce04d51662e8 100644
--- a/system/Config/Factories.php
+++ b/system/Config/Factories.php
@@ -28,7 +28,7 @@
  * @method static Model|null      models(string $alias, array $options = [], ?ConnectionInterface &$conn = null)
  * @see \CodeIgniter\Config\FactoriesTest
  */
-class Factories
+final class Factories
 {
     /**
      * Store of component-specific options, usually
@@ -36,7 +36,7 @@ class Factories
      *
      * @var array<string, array<string, bool|string|null>>
      */
-    protected static $options = [];
+    private static $options = [];
 
     /**
      * Explicit options for the Config
@@ -65,7 +65,7 @@ class Factories
      * @var array<string, array<string, string>>
      * @phpstan-var array<string, array<string, class-string>>
      */
-    protected static $aliases = [];
+    private static $aliases = [];
 
     /**
      * Store for instances of any component that
@@ -79,7 +79,7 @@ class Factories
      * @var array<string, array<string, object>>
      * @phpstan-var  array<string, array<class-string, object>>
      */
-    protected static $instances = [];
+    private static $instances = [];
 
     /**
      * Whether the component instances are updated?
@@ -88,7 +88,7 @@ class Factories
      *
      * @internal For caching only
      */
-    protected static $updated = [];
+    private static $updated = [];
 
     /**
      * Define the class to load. You can *override* the concrete class.
@@ -252,7 +252,7 @@ private static function isConfig(string $component): bool
      * @param array  $options The array of component-specific directives
      * @param string $alias   Class alias. See the $aliases property.
      */
-    protected static function locateClass(array $options, string $alias): ?string
+    private static function locateClass(array $options, string $alias): ?string
     {
         // Check for low-hanging fruit
         if (
@@ -328,7 +328,7 @@ private static function isNamespaced(string $alias): bool
      * @param array  $options The array of component-specific directives
      * @param string $alias   Class alias. See the $aliases property.
      */
-    protected static function verifyPreferApp(array $options, string $alias): bool
+    private static function verifyPreferApp(array $options, string $alias): bool
     {
         // Anything without that restriction passes
         if (! $options['preferApp']) {
@@ -349,7 +349,7 @@ protected static function verifyPreferApp(array $options, string $alias): bool
      * @param array  $options The array of component-specific directives
      * @param string $alias   Class alias. See the $aliases property.
      */
-    protected static function verifyInstanceOf(array $options, string $alias): bool
+    private static function verifyInstanceOf(array $options, string $alias): bool
     {
         // Anything without that restriction passes
         if (! $options['instanceOf']) {
diff --git a/user_guide_src/source/changelogs/v4.5.0.rst b/user_guide_src/source/changelogs/v4.5.0.rst
index 1a1ac6fe901a..3dbb0ea42a59 100644
--- a/user_guide_src/source/changelogs/v4.5.0.rst
+++ b/user_guide_src/source/changelogs/v4.5.0.rst
@@ -34,6 +34,12 @@ Due to a bug fix, the behavior has changed so that options passed to the outer
 ``group()`` are merged with the options of the inner ``group()``.
 See :ref:`Upgrading Guide <upgrade-450-nested-route-groups-and-options>` for details.
 
+Factories class
+---------------
+
+:doc:`../concepts/factories` has been changed to a final class. It is a static
+class, and even if it were extended, there is no way to replace it.
+
 Others
 ------
 
diff --git a/user_guide_src/source/installation/upgrade_450.rst b/user_guide_src/source/installation/upgrade_450.rst
index db022059d585..56b1f37c011e 100644
--- a/user_guide_src/source/installation/upgrade_450.rst
+++ b/user_guide_src/source/installation/upgrade_450.rst
@@ -119,6 +119,13 @@ has been removed.
 
 If you extneds ``BaseModel``, implement the ``getIdValue()`` method in the child class.
 
+Factories
+=========
+
+:doc:`../concepts/factories` has been changed to a final class.
+In the unlikely event, you have inherited the Factories, stop inheriting and
+copy the code into your Factories class.
+
 Removed Deprecated Items
 ========================