diff --git a/packages/domain-event-outbox/src/RekalogikaDomainEventOutboxBundle.php b/packages/domain-event-outbox/src/RekalogikaDomainEventOutboxBundle.php
index d2c520a..214154c 100644
--- a/packages/domain-event-outbox/src/RekalogikaDomainEventOutboxBundle.php
+++ b/packages/domain-event-outbox/src/RekalogikaDomainEventOutboxBundle.php
@@ -20,7 +20,7 @@
 
 class RekalogikaDomainEventOutboxBundle extends Bundle
 {
-    public function build(ContainerBuilder $container)
+    public function build(ContainerBuilder $container): void
     {
         parent::build($container);
 
diff --git a/packages/domain-event/src/RekalogikaDomainEventBundle.php b/packages/domain-event/src/RekalogikaDomainEventBundle.php
index bef454a..e896cd7 100644
--- a/packages/domain-event/src/RekalogikaDomainEventBundle.php
+++ b/packages/domain-event/src/RekalogikaDomainEventBundle.php
@@ -21,7 +21,7 @@
 
 class RekalogikaDomainEventBundle extends Bundle
 {
-    public function build(ContainerBuilder $container)
+    public function build(ContainerBuilder $container): void
     {
         parent::build($container);