diff --git messaging.mail.inc messaging.mail.inc
index e210879..b3e0ae9 100644
--- messaging.mail.inc
+++ messaging.mail.inc
@@ -64,7 +64,7 @@ function messaging_mail_prepare($destination, $message, $params, $alter = TRUE)
  */
 function messaging_mail_headers($message, $params) {
   
-  $headers = !empty($params['headers']) ? $params['headers'] : array();
+  $headers = !empty($params['headers']) && is_array($params['headers']) ? $params['headers'] : array();
   
   // Add some default headers
   $headers += array(