diff --git a/system/Autoloader/Autoloader.php b/system/Autoloader/Autoloader.php
index dc0b72cd6122..d5c155685e12 100644
--- a/system/Autoloader/Autoloader.php
+++ b/system/Autoloader/Autoloader.php
@@ -260,9 +260,6 @@ public function loadClassmap(string $class): void
      */
     public function loadClass(string $class): void
     {
-        $class = trim($class, '\\');
-        $class = str_ireplace('.php', '', $class);
-
         $this->loadInNamespace($class);
     }
 
diff --git a/tests/system/Autoloader/AutoloaderTest.php b/tests/system/Autoloader/AutoloaderTest.php
index d877d66e406d..4c81537dbf09 100644
--- a/tests/system/Autoloader/AutoloaderTest.php
+++ b/tests/system/Autoloader/AutoloaderTest.php
@@ -20,7 +20,6 @@
 use Config\Modules;
 use Config\Services;
 use InvalidArgumentException;
-use PHPUnit\Framework\MockObject\MockObject;
 use RuntimeException;
 use UnnamespacedClass;
 
@@ -34,6 +33,10 @@ final class AutoloaderTest extends CIUnitTestCase
     use ReflectionHelper;
 
     private Autoloader $loader;
+
+    /**
+     * @phpstan-var Closure(string): (false|string)
+     */
     private Closure $classLoader;
 
     protected function setUp(): void
@@ -146,15 +149,6 @@ public function testMatchesWithPrecedingSlash(): void
         $this->assertSame($expected, $actual);
     }
 
-    public function testMatchesWithFileExtension(): void
-    {
-        /** @var Autoloader&MockObject $classLoader */
-        $classLoader = $this->getMockBuilder(Autoloader::class)->onlyMethods(['loadInNamespace'])->getMock();
-        $classLoader->expects($this->once())->method('loadInNamespace')->with(Home::class);
-
-        $classLoader->loadClass('\App\Controllers\Home.php');
-    }
-
     public function testMissingFile(): void
     {
         $this->assertFalse(($this->classLoader)('\App\Missing\Classname'));
diff --git a/user_guide_src/source/changelogs/v4.4.0.rst b/user_guide_src/source/changelogs/v4.4.0.rst
index 5cf06105d29f..4747e953fc29 100644
--- a/user_guide_src/source/changelogs/v4.4.0.rst
+++ b/user_guide_src/source/changelogs/v4.4.0.rst
@@ -58,6 +58,12 @@ Property Name
 
 The property ``Factories::$basenames`` has been renamed to ``$aliases``.
 
+Autoloader
+----------
+
+Previously, CodeIgniter's autoloader allowed loading class names ending with the `.php` extension. This means instantiating objects like `new Foo.php()` was possible
+and would instantiate as `new Foo()`. Since `Foo.php` is an invalid class name, this behavior of the autoloader is changed. Now, instantiating such classes would fail.
+
 .. _v440-interface-changes:
 
 Interface Changes