diff --git a/src/DependencyInjection/Compiler/Endpoints/DefaultEndpointWiringPass.php b/src/DependencyInjection/Compiler/Endpoints/DefaultEndpointWiringPass.php
index f0994e4..bbcfba4 100644
--- a/src/DependencyInjection/Compiler/Endpoints/DefaultEndpointWiringPass.php
+++ b/src/DependencyInjection/Compiler/Endpoints/DefaultEndpointWiringPass.php
@@ -10,7 +10,7 @@
 final class DefaultEndpointWiringPass implements CompilerPassInterface
 {
     //@todo https://github.com/symfony/symfony/blob/master/src/Symfony/Component/DependencyInjection/Tests/Compiler/RemoveUnusedDefinitionsPassTest.php
-    public function process(ContainerBuilder $container)
+    public function process(ContainerBuilder $container):void
     {
         $endpointDefinition = $container->getDefinition('overblog_graphiql.controller.graphql.endpoint');
 
diff --git a/src/DependencyInjection/Compiler/Endpoints/OverblogGraphQLBundleEndpointWiringPass.php b/src/DependencyInjection/Compiler/Endpoints/OverblogGraphQLBundleEndpointWiringPass.php
index 693f7b5..9d5f1b3 100644
--- a/src/DependencyInjection/Compiler/Endpoints/OverblogGraphQLBundleEndpointWiringPass.php
+++ b/src/DependencyInjection/Compiler/Endpoints/OverblogGraphQLBundleEndpointWiringPass.php
@@ -9,7 +9,7 @@
 
 final class OverblogGraphQLBundleEndpointWiringPass implements CompilerPassInterface
 {
-    public function process(ContainerBuilder $container)
+    public function process(ContainerBuilder $container):void
     {
         $bundles = $container->getParameter('kernel.bundles_metadata');