diff --git a/README.md b/README.md
index 52b728f..014bbd2 100644
--- a/README.md
+++ b/README.md
@@ -1,34 +1,45 @@
 # Polylang PHPStan
 
 This package provides a [PHPStan](https://phpstan.org/) extension for [Polylang](https://wordpress.org/plugins/polylang/) and [Polylang Pro](https://polylang.pro).
-It's should be used in combination with [Polylang Stubs](https://github.com/polylang/polylang-stubs/).
+It should be used in combination with [Polylang Stubs](https://github.com/polylang/polylang-stubs/).
 
-### Requirements
+## Requirements
 
-- PHP >=7.1
+- PHP 8+
 
-### Installation
+## Installation
 
 Require this package as a development dependency with Composer.
 
+> [!TIP]
+> `polylang/polylang-stubs` is optional but strongly recommended.
+
 ```bash
 composer require --dev wpsyntex/polylang-phpstan
 composer require --dev wpsyntex/polylang-stubs
 ```
 
-### Configuration
+## Configuration
+
+### Adding the extension
 
 Include the extension and stubs in the PHPStan configuration file.
 
+> [!IMPORTANT]
+> Prior to version 2.1 (included), `polylang/polylang-stubs` is automatically loaded.
+> Starting from version 2.2, it must be configured manually.
+
 ```yaml
 includes:
   - vendor/wpsyntex/polylang-phpstan/extension.neon
 parameters:
-  bootstrapFiles:
+  stubFiles:
     - vendor/wpsyntex/polylang-stubs/polylang-stubs.php
 ```
 
-Opt-in for WordPress stubs override.
+### Opt in to WordPress stubs overrides
+
+The `stubs/wordpress-override.php` file provides corrected type definitions for specific WordPress functions that have imprecise or incorrect type hints in the standard WordPress stubs (currently `sanitize_key()`, `maybe_serialize()`, and `sanitize_text_field()`).
 
 ```yaml
   stubFiles:
diff --git a/bootstrap.php b/bootstrap.php
index ea47878..68ab092 100644
--- a/bootstrap.php
+++ b/bootstrap.php
@@ -33,7 +33,7 @@
 define( 'POLYLANG', 'Polylang' );
 define( 'POLYLANG_BASENAME', 'polylang/polylang.php' );
 define( 'POLYLANG_DIR', './' );
-define( 'POLYLANG_VERSION', '3.0' ); // Must also be defined as dynamic in config file.
+define( 'POLYLANG_VERSION', '3.8' ); // Must also be defined as dynamic in config file.
 define( 'PLL_COOKIE', 'pll_language' );
 define( 'PLL_LOCAL_DIR', './wp-content/polylang' );
 define( 'PLL_ADMIN', false ); // Must also be defined as dynamic in config file.
diff --git a/extension.neon b/extension.neon
index 2e5f69a..76f4fcc 100644
--- a/extension.neon
+++ b/extension.neon
@@ -27,9 +27,9 @@ includes:
 	- ../../szepeviktor/phpstan-wordpress/extension.neon
 parameters:
 	bootstrapFiles:
-		- %rootDir%/../../php-stubs/wordpress-stubs/wordpress-stubs.php
-		- %rootDir%/../../wpsyntex/polylang-stubs/polylang-stubs.php
 		- bootstrap.php
+	stubFiles:
+		- %rootDir%/../../php-stubs/wordpress-stubs/wordpress-stubs.php
 	dynamicConstantNames:
 		- POLYLANG_VERSION
 		- PLL_ADMIN
diff --git a/tests/DynamicReturnTypeExtensionTest.php b/tests/DynamicReturnTypeExtensionTest.php
index 74def12..6984e8c 100644
--- a/tests/DynamicReturnTypeExtensionTest.php
+++ b/tests/DynamicReturnTypeExtensionTest.php
@@ -30,6 +30,9 @@ public function testFileAsserts(string $assertType, string $file, ...$args): voi
 	public static function getAdditionalConfigFiles(): array
 	{
 		// phpstan.neon or extension.neon use relative paths, so we need to use a fake vendor directory regarding szepeviktor/phpstan-wordpress dependency.
-		return [dirname(__DIR__) . '/vendor/wpsyntex/polylang-phpstan/extension.neon'];
+		return [
+			dirname(__DIR__) . '/vendor/wpsyntex/polylang-phpstan/extension.neon',
+			dirname(__DIR__) . '/vendor/wpsyntex/polylang-phpstan/test-extension.neon',
+		];
 	}
 }
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index dab0cc5..81b56d3 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -14,6 +14,7 @@
 
 // Copy package to a fake vendor directory.
 copy(dirname(__DIR__) . '/extension.neon', $helperDirectory . '/extension.neon');
+copy(dirname(__DIR__) . '/tests/test-extension.neon', $helperDirectory . '/test-extension.neon');
 copy(dirname(__DIR__) . '/bootstrap.php', $helperDirectory . '/bootstrap.php');
 
 require_once dirname(__DIR__) . '/vendor/autoload.php';
diff --git a/tests/test-extension.neon b/tests/test-extension.neon
new file mode 100644
index 0000000..2e72431
--- /dev/null
+++ b/tests/test-extension.neon
@@ -0,0 +1,3 @@
+parameters:
+	bootstrapFiles:
+		- %rootDir%/../../wpsyntex/polylang-stubs/polylang-stubs.php