diff --git a/reference/imap/functions/imap-append.xml b/reference/imap/functions/imap-append.xml
index a2895901d3..f948c82b86 100644
--- a/reference/imap/functions/imap-append.xml
+++ b/reference/imap/functions/imap-append.xml
@@ -13,6 +13,7 @@
    <methodparam><type>string</type><parameter>mailbox</parameter></methodparam>
    <methodparam><type>string</type><parameter>message</parameter></methodparam>
    <methodparam choice="opt"><type>string</type><parameter>options</parameter><initializer>NULL</initializer></methodparam>
+   <methodparam choice="opt"><type>string</type><parameter>internal_date</parameter><initializer>NULL</initializer></methodparam>
   </methodsynopsis>
   <para>
    Appends a string <parameter>message</parameter> to the specified <parameter>mailbox</parameter>. 
@@ -54,6 +55,14 @@
       </para>
      </listitem>
     </varlistentry>
+    <varlistentry>
+     <term><parameter>internal_date</parameter></term>
+     <listitem>
+      <para>
+       If this parameter is set, it will set the INTERNALDATE on the appended message.  The parameter should be a date string that conforms to the rfc2060 specifications for a date_time value.
+      </para>
+     </listitem>
+    </varlistentry>
    </variablelist>
   </para>
  </refsect1>