diff --git a/reference/classobj/functions/method-exists.xml b/reference/classobj/functions/method-exists.xml
index 41c7cf9f7d..92593348bb 100644
--- a/reference/classobj/functions/method-exists.xml
+++ b/reference/classobj/functions/method-exists.xml
@@ -9,7 +9,7 @@
   &reftitle.description;
   <methodsynopsis>
    <type>bool</type><methodname>method_exists</methodname>
-   <methodparam><type>mixed</type><parameter>object</parameter></methodparam>
+   <methodparam><type class="union"><type>string</type><type>object</type></type><parameter>object</parameter></methodparam>
    <methodparam><type>string</type><parameter>method_name</parameter></methodparam>
   </methodsynopsis>
   <para>