diff --git a/system/Autoloader/Autoloader.php b/system/Autoloader/Autoloader.php
index 86d922c33302..65c535e8611e 100644
--- a/system/Autoloader/Autoloader.php
+++ b/system/Autoloader/Autoloader.php
@@ -21,7 +21,7 @@
 use Config\Autoload;
 use Config\Kint as KintConfig;
 use Config\Modules;
-use Kint;
+use Kint\Kint;
 use Kint\Renderer\CliRenderer;
 use Kint\Renderer\RichRenderer;
 
@@ -67,21 +67,21 @@ class Autoloader
     /**
      * Stores namespaces as key, and path as values.
      *
-     * @var array<string, list<string>>
+     * @var array<non-empty-string, list<non-empty-string>>
      */
     protected $prefixes = [];
 
     /**
      * Stores class name as key, and path as values.
      *
-     * @var array<class-string, string>
+     * @var array<class-string, non-empty-string>
      */
     protected $classmap = [];
 
     /**
      * Stores files as a list.
      *
-     * @var list<string>
+     * @var list<non-empty-string>
      */
     protected $files = [];
 
@@ -89,7 +89,7 @@ class Autoloader
      * Stores helper list.
      * Always load the URL helper, it should be used in most apps.
      *
-     * @var list<string>
+     * @var list<non-empty-string>
      */
     protected $helpers = ['url'];
 
@@ -147,36 +147,35 @@ private function loadComposerAutoloader(Modules $modules): void
 
         // Should we load through Composer's namespaces, also?
         if ($modules->discoverInComposer) {
-            // @phpstan-ignore-next-line
-            $this->loadComposerNamespaces($composer, $modules->composerPackages ?? []);
+            $composerPackages = $modules->composerPackages;
+            $this->loadComposerNamespaces($composer, $composerPackages ?? []);
         }
 
         unset($composer);
     }
 
     /**
-     * Register the loader with the SPL autoloader stack.
+     * Register the loader with the SPL autoloader stack
+     * in the following order:
+     *
+     * 1. Classmap loader
+     * 2. PSR-4 autoloader
+     * 3. Non-class files
      *
      * @return void
      */
     public function register()
     {
-        // Register classmap loader for the files in our class map.
         spl_autoload_register($this->loadClassmap(...), true);
-
-        // Register the PSR-4 autoloader.
         spl_autoload_register($this->loadClass(...), true);
 
-        // Load our non-class files
         foreach ($this->files as $file) {
             $this->includeFile($file);
         }
     }
 
     /**
-     * Unregister autoloader.
-     *
-     * This method is for testing.
+     * Unregisters the autoloader from the SPL autoload stack.
      */
     public function unregister(): void
     {
@@ -187,7 +186,7 @@ public function unregister(): void
     /**
      * Registers namespaces with the autoloader.
      *
-     * @param array<string, list<string>|string>|string $namespace
+     * @param array<non-empty-string, list<non-empty-string>|non-empty-string>|non-empty-string $namespace
      *
      * @return $this
      */
@@ -219,7 +218,7 @@ public function addNamespace($namespace, ?string $path = null)
      *
      * If a prefix param is set, returns only paths to the given prefix.
      *
-     * @return ($prefix is null ? array<string, list<string>> : list<string>)
+     * @return ($prefix is null ? array<non-empty-string, list<non-empty-string>> : list<non-empty-string>)
      */
     public function getNamespace(?string $prefix = null)
     {
@@ -247,6 +246,8 @@ public function removeNamespace(string $namespace)
     /**
      * Load a class using available class mapping.
      *
+     * @param class-string $class The fully qualified class name.
+     *
      * @internal For `spl_autoload_register` use.
      */
     public function loadClassmap(string $class): void
@@ -261,9 +262,9 @@ public function loadClassmap(string $class): void
     /**
      * Loads the class file for a given class name.
      *
-     * @internal For `spl_autoload_register` use.
+     * @param class-string $class The fully qualified class name.
      *
-     * @param string $class The fully qualified class name.
+     * @internal For `spl_autoload_register` use.
      */
     public function loadClass(string $class): void
     {
@@ -273,9 +274,9 @@ public function loadClass(string $class): void
     /**
      * Loads the class file for a given class name.
      *
-     * @param string $class The fully-qualified class name
+     * @param class-string $class The fully qualified class name.
      *
-     * @return false|string The mapped file name on success, or boolean false on fail
+     * @return false|non-empty-string The mapped file name on success, or boolean false on fail
      */
     protected function loadInNamespace(string $class)
     {
@@ -293,21 +294,20 @@ protected function loadInNamespace(string $class)
                     $filePath = $directory . $relativeClassPath . '.php';
                     $filename = $this->includeFile($filePath);
 
-                    if ($filename) {
+                    if ($filename !== false) {
                         return $filename;
                     }
                 }
             }
         }
 
-        // never found a mapped file
         return false;
     }
 
     /**
      * A central way to include a file. Split out primarily for testing purposes.
      *
-     * @return false|string The filename on success, false if the file is not loaded
+     * @return false|non-empty-string The filename on success, false if the file is not loaded
      */
     protected function includeFile(string $file)
     {
diff --git a/system/Autoloader/FileLocator.php b/system/Autoloader/FileLocator.php
index 13ecb817a56c..f67708a4e836 100644
--- a/system/Autoloader/FileLocator.php
+++ b/system/Autoloader/FileLocator.php
@@ -44,7 +44,7 @@ public function __construct(Autoloader $autoloader)
      * Attempts to locate a file by examining the name for a namespace
      * and looking through the PSR-4 namespaced files that we know about.
      *
-     * @param string                $file   The relative file path or namespaced file to
+     * @param non-empty-string      $file   The relative file path or namespaced file to
      *                                      locate. If not namespaced, search in the app
      *                                      folder.
      * @param non-empty-string|null $folder The folder within the namespace that we should
@@ -53,7 +53,7 @@ public function __construct(Autoloader $autoloader)
      *                                      folder.
      * @param string                $ext    The file extension the file should have.
      *
-     * @return false|string The path to the file, or false if not found.
+     * @return false|non-empty-string The path to the file, or false if not found.
      */
     public function locateFile(string $file, ?string $folder = null, string $ext = 'php')
     {
@@ -156,9 +156,11 @@ public function getClassname(string $file): string
                 $dlm = false;
             }
 
-            if (($tokens[$i - 2][0] === T_CLASS || (isset($tokens[$i - 2][1]) && $tokens[$i - 2][1] === 'phpclass'))
+            if (
+                ($tokens[$i - 2][0] === T_CLASS || (isset($tokens[$i - 2][1]) && $tokens[$i - 2][1] === 'phpclass'))
                 && $tokens[$i - 1][0] === T_WHITESPACE
-                && $token[0] === T_STRING) {
+                && $token[0] === T_STRING
+            ) {
                 $className = $token[1];
                 break;
             }
@@ -184,7 +186,7 @@ public function getClassname(string $file): string
      *      'app/Modules/bar/Config/Routes.php',
      *  ]
      *
-     * @return list<string>
+     * @return list<non-empty-string>
      */
     public function search(string $path, string $ext = 'php', bool $prioritizeApp = true): array
     {
@@ -213,7 +215,6 @@ public function search(string $path, string $ext = 'php', bool $prioritizeApp =
             $foundPaths = [...$foundPaths, ...$appPaths];
         }
 
-        // Remove any duplicates
         return array_values(array_unique($foundPaths));
     }
 
@@ -236,13 +237,12 @@ protected function ensureExt(string $path, string $ext): string
     /**
      * Return the namespace mappings we know about.
      *
-     * @return array<int, array<string, string>>
+     * @return list<array{prefix: non-empty-string, path: non-empty-string}>
      */
     protected function getNamespaces()
     {
         $namespaces = [];
 
-        // Save system for last
         $system = [];
 
         foreach ($this->autoloader->getNamespace() as $prefix => $paths) {
@@ -263,6 +263,7 @@ protected function getNamespaces()
             }
         }
 
+        // Save system for last
         return array_merge($namespaces, $system);
     }
 
@@ -295,19 +296,17 @@ public function findQualifiedNameFromPath(string $path)
                     );
 
                 // Remove the file extension (.php)
-                /** @var class-string */
+                /** @var class-string $className */
                 $className = mb_substr($className, 0, -4);
 
                 if (in_array($className, $this->invalidClassnames, true)) {
                     continue;
                 }
 
-                // Check if this exists
                 if (class_exists($className)) {
                     return $className;
                 }
 
-                // If the class does not exist, it is an invalid classname.
                 $this->invalidClassnames[] = $className;
             }
         }
@@ -353,11 +352,11 @@ public function listFiles(string $path): array
      * Scans the provided namespace, returning a list of all files
      * that are contained within the sub path specified by $path.
      *
-     * @return list<string> List of file paths
+     * @return list<non-empty-string> List of file paths
      */
     public function listNamespaceFiles(string $prefix, string $path): array
     {
-        if ($path === '' || ($prefix === '')) {
+        if ($path === '' || $prefix === '') {
             return [];
         }
 
diff --git a/system/Autoloader/FileLocatorCached.php b/system/Autoloader/FileLocatorCached.php
index 8b17399444c6..0aa267b2a84b 100644
--- a/system/Autoloader/FileLocatorCached.php
+++ b/system/Autoloader/FileLocatorCached.php
@@ -117,7 +117,7 @@ public function getClassname(string $file): string
     }
 
     /**
-     * @return list<string>
+     * @return list<non-empty-string>
      */
     public function search(string $path, string $ext = 'php', bool $prioritizeApp = true): array
     {
diff --git a/system/Autoloader/FileLocatorInterface.php b/system/Autoloader/FileLocatorInterface.php
index 8f6129abee17..0422ec2519db 100644
--- a/system/Autoloader/FileLocatorInterface.php
+++ b/system/Autoloader/FileLocatorInterface.php
@@ -23,7 +23,7 @@ interface FileLocatorInterface
      * Attempts to locate a file by examining the name for a namespace
      * and looking through the PSR-4 namespaced files that we know about.
      *
-     * @param string                $file   The relative file path or namespaced file to
+     * @param non-empty-string      $file   The relative file path or namespaced file to
      *                                      locate. If not namespaced, search in the app
      *                                      folder.
      * @param non-empty-string|null $folder The folder within the namespace that we should
@@ -32,12 +32,14 @@ interface FileLocatorInterface
      *                                      folder.
      * @param string                $ext    The file extension the file should have.
      *
-     * @return false|string The path to the file, or false if not found.
+     * @return false|non-empty-string The path to the file, or false if not found.
      */
     public function locateFile(string $file, ?string $folder = null, string $ext = 'php');
 
     /**
      * Examines a file and returns the fully qualified class name.
+     *
+     * @param non-empty-string $file
      */
     public function getClassname(string $file): string;
 
@@ -54,7 +56,7 @@ public function getClassname(string $file): string;
      *      'app/Modules/bar/Config/Routes.php',
      *  ]
      *
-     * @return list<string>
+     * @return list<non-empty-string>
      */
     public function search(string $path, string $ext = 'php', bool $prioritizeApp = true): array;
 
diff --git a/tests/system/Autoloader/AutoloaderTest.php b/tests/system/Autoloader/AutoloaderTest.php
index af5340400160..cd73356958fe 100644
--- a/tests/system/Autoloader/AutoloaderTest.php
+++ b/tests/system/Autoloader/AutoloaderTest.php
@@ -394,7 +394,7 @@ public function testAutoloaderLoadsNonClassFiles(): void
 
         $this->assertTrue(function_exists('autoload_foo'));
         $this->assertSame('I am autoloaded by Autoloader through $files!', autoload_foo());
-        $this->assertTrue(defined('AUTOLOAD_CONSTANT'));
+        $this->assertTrue(defined('AUTOLOAD_CONSTANT')); // @phpstan-ignore method.alreadyNarrowedType
         $this->assertSame('foo', AUTOLOAD_CONSTANT);
 
         $loader->unregister();
diff --git a/utils/phpstan-baseline/loader.neon b/utils/phpstan-baseline/loader.neon
index 4754c3cd6c9b..00cce6e6c73b 100644
--- a/utils/phpstan-baseline/loader.neon
+++ b/utils/phpstan-baseline/loader.neon
@@ -1,4 +1,4 @@
-# total 3075 errors
+# total 3074 errors
 includes:
     - argument.type.neon
     - assign.propertyType.neon
diff --git a/utils/phpstan-baseline/method.alreadyNarrowedType.neon b/utils/phpstan-baseline/method.alreadyNarrowedType.neon
index 23132319175b..f980738a073a 100644
--- a/utils/phpstan-baseline/method.alreadyNarrowedType.neon
+++ b/utils/phpstan-baseline/method.alreadyNarrowedType.neon
@@ -1,4 +1,4 @@
-# total 24 errors
+# total 23 errors
 
 parameters:
     ignoreErrors:
@@ -7,11 +7,6 @@ parameters:
             count: 1
             path: ../../admin/starter/tests/unit/HealthTest.php
 
-        -
-            message: '#^Call to method PHPUnit\\Framework\\Assert\:\:assertTrue\(\) with bool will always evaluate to true\.$#'
-            count: 1
-            path: ../../tests/system/Autoloader/AutoloaderTest.php
-
         -
             message: '#^Call to method PHPUnit\\Framework\\Assert\:\:assertIsBool\(\) with bool will always evaluate to true\.$#'
             count: 1