diff --git a/reference/spl/arrayobject/serialize.xml b/reference/spl/arrayobject/serialize.xml
index e525c29672..de34231f10 100644
--- a/reference/spl/arrayobject/serialize.xml
+++ b/reference/spl/arrayobject/serialize.xml
@@ -10,7 +10,7 @@
  <refsect1 role="description">
   &reftitle.description;
   <methodsynopsis>
-   <modifier>public</modifier> <type>void</type><methodname>ArrayObject::serialize</methodname>
+   <modifier>public</modifier> <type>string</type><methodname>ArrayObject::serialize</methodname>
    <void />
   </methodsynopsis>
   <para>