diff --git a/composer.json b/composer.json
index 302e2e7a..3f7b174a 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,7 @@
         "php": "^7.4 || ^8.0",
         "doctrine/cache": "^1.11 || ^2.0",
         "doctrine/dbal": "^3.7.0 || ^4.0",
-        "doctrine/persistence": "^2.2 || ^3",
+        "doctrine/persistence": "^2.2 || ^3 || ^4",
         "doctrine/sql-formatter": "^1.0.1",
         "symfony/cache": "^5.4 || ^6.0 || ^7.0",
         "symfony/config": "^5.4 || ^6.0 || ^7.0",
diff --git a/src/Mapping/MappingDriver.php b/src/Mapping/MappingDriver.php
index 88cfec04..6aac1c24 100644
--- a/src/Mapping/MappingDriver.php
+++ b/src/Mapping/MappingDriver.php
@@ -21,7 +21,7 @@ public function __construct(MappingDriverInterface $driver, ContainerInterface $
     /**
      * {@inheritDoc}
      */
-    public function getAllClassNames()
+    public function getAllClassNames(): array
     {
         return $this->driver->getAllClassNames();
     }