diff --git a/Classes/Finishers/EmailFinisher.php b/Classes/Finishers/EmailFinisher.php
index 5f2436f..490f707 100644
--- a/Classes/Finishers/EmailFinisher.php
+++ b/Classes/Finishers/EmailFinisher.php
@@ -167,7 +167,7 @@ protected function executeInternal()
         }
     }
 
-    protected function addMessages(SwiftMailerMessage $mail, array $messages): void
+    protected function addMessages(SwiftMailerMessage $mail, array $messages)
     {
         foreach ($messages as $messageFormat => $message) {
             if (count($messages) === 1) {