diff --git a/inc/iSchedule.php b/inc/iSchedule.php
index ac3fa7f7..643142ff 100644
--- a/inc/iSchedule.php
+++ b/inc/iSchedule.php
@@ -434,7 +434,7 @@ class iSchedule
       $headers['Content-Type'] = 'text/calendar; component=' . $component ;
       if ( $method )
         $headers['Content-Type'] .= '; method=' . $method;
-      $headers['DKIM-Signature'] = $this->signDKIM ( $headers, $body );
+      $headers['DKIM-Signature'] = $this->signDKIM ( $headers, $data );
       if ( $headers['DKIM-Signature'] == false )
         return false;
       $request_headers = array ( );