diff --git a/reference/zip/functions/zip-open.xml b/reference/zip/functions/zip-open.xml
index a7066438ee..8f38c9b803 100644
--- a/reference/zip/functions/zip-open.xml
+++ b/reference/zip/functions/zip-open.xml
@@ -9,7 +9,7 @@
  <refsect1 role="description">
   &reftitle.description;
   <methodsynopsis>
-   <type>resource</type><methodname>zip_open</methodname>
+   <type class="union"><type>resource</type><type>int</type><type>false</type></type><methodname>zip_open</methodname>
    <methodparam><type>string</type><parameter>filename</parameter></methodparam>
   </methodsynopsis>
   <para>
@@ -36,8 +36,8 @@
   <para>
    Returns a resource handle for later use with
    <function>zip_read</function> and <function>zip_close</function>
-   or returns the number of error if <parameter>filename</parameter> does not
-   exist or in case of other error.
+   or returns either &false; or the number of error if <parameter>filename</parameter>
+   does not exist or in case of other error.
   </para>
  </refsect1>