diff --git a/ApiBundle.php b/ApiBundle.php
index 5dd1c46..be1d68e 100644
--- a/ApiBundle.php
+++ b/ApiBundle.php
@@ -3,11 +3,12 @@
 namespace Bookboon\ApiBundle;
 
 use Bookboon\ApiBundle\DependencyInjection\BookboonApiExtension;
+use Symfony\Component\DependencyInjection\Extension\ExtensionInterface;
 use Symfony\Component\HttpKernel\Bundle\Bundle;
 
 class ApiBundle extends Bundle
 {
-    public function getContainerExtension()
+    public function getContainerExtension() : ?ExtensionInterface
     {
         return new BookboonApiExtension();
     }
diff --git a/DependencyInjection/BookboonApiExtension.php b/DependencyInjection/BookboonApiExtension.php
index 4731d6e..ebb7934 100644
--- a/DependencyInjection/BookboonApiExtension.php
+++ b/DependencyInjection/BookboonApiExtension.php
@@ -39,12 +39,12 @@ public function load(array $configs, ContainerBuilder $container)
         $loader->load('services.yml');
     }
 
-    public function getAlias()
+    public function getAlias() : string
     {
         return 'bookboonapi';
     }
 
-    public function getXsdValidationBasePath()
+    public function getXsdValidationBasePath() : string
     {
         return 'http://bookboon.com/schema/dic/' . $this->getAlias();
     }
diff --git a/composer.json b/composer.json
index e24f278..adea195 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
         "symfony/http-kernel": "^5.0|^6.0",
         "symfony/config": "^5.0|^6.0",
         "symfony/cache": "^5.0|^6.0",
-        "bookboon/jsonld-client": "^2.4",
+        "bookboon/jsonld-client": "^2.6",
         "bookboon/api-models-php": "^1.2",
         "bookboon/oauth2-client-php": "^1.0"
     },