diff --git a/src/contacts/Contacts.php b/src/contacts/Contacts.php
index 16c77fa..e245e7d 100644
--- a/src/contacts/Contacts.php
+++ b/src/contacts/Contacts.php
@@ -3,6 +3,7 @@
 namespace de\xqueue\maileon\api\client\contacts;
 
 use ArrayIterator;
+use Traversable;
 use de\xqueue\maileon\api\client\xml\AbstractXMLWrapper;
 use IteratorAggregate;
 use SimpleXMLElement;
@@ -39,9 +40,9 @@ public function addContact($contact)
     }
 
     /**
-     * @return ArrayIterator an iterator for the contacts in this list of contacts
+     * @return Traversable an iterator for the contacts in this list of contacts
      */
-    public function getIterator()
+    public function getIterator(): Traversable
     {
         return new ArrayIterator($this->contacts);
     }