diff --git a/lib/session.js b/lib/session.js
index 058d6bc..e36b11f 100644
--- a/lib/session.js
+++ b/lib/session.js
@@ -281,7 +281,7 @@ function session(sock) {
 
 			smsObj.smsId = smsData.smsId;
 
-			returnObj.sendReturn(pduObj, {'message_id': smsObj.smsId});
+			returnObj.sendReturn(pduObj, 'ESME_ROK', {'message_id': smsObj.smsId});
 		}
 
 		returnObj.emit('sms', smsObj, smsReceived);