--- loncom/lti/ltiutils.pm	2018/08/14 21:42:36	1.15
+++ loncom/lti/ltiutils.pm	2019/03/31 18:48:33	1.16
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Utility functions for managing LON-CAPA LTI interactions 
 #
-# $Id: ltiutils.pm,v 1.15 2018/08/14 21:42:36 raeburn Exp $
+# $Id: ltiutils.pm,v 1.16 2019/03/31 18:48:33 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -790,6 +790,7 @@ END
                            nonce => $nonce,
                            body_hash => $bodyhash,
         );
+        $gradereq->add_required_message_params('body_hash');
         $gradereq->sign();
         $request = HTTP::Request->new(
 	               $gradereq->request_method,