--- a/dom/nfc/gonk/Nfc.js
+++ b/dom/nfc/gonk/Nfc.js
@@ -477,17 +477,17 @@ Nfc.prototype = {
             gMessageManager.onPeerEvent(NFC.PEER_EVENT_FOUND, message.sessionToken);
           }
         } else {
           gMessageManager.onTagFound(message);
         }
 
         let sysMsg = new NfcTechDiscoveredSysMsg(message.sessionToken,
                                                  message.isP2P,
-                                                 message.records);
+                                                 message.records || null);
         gSystemMessenger.broadcastMessage("nfc-manager-tech-discovered", sysMsg);
         break;
       case "TechLostNotification":
         message.type = "techLost";
 
         // Update the upper layers with a session token (alias)
         message.sessionToken = SessionHelper.getToken(message.sessionId);
         if (SessionHelper.isP2PSession(message.sessionId)) {

--- a/dom/nfc/nsNfc.js
+++ b/dom/nfc/nsNfc.js
@@ -568,16 +568,20 @@ NFCTechDiscoveredWrapper.prototype = {
   // nsISystemMessagesWrapper implementation.
   wrapMessage: function wrapMessage(aMessage, aWindow) {
     aMessage = Cu.cloneInto(aMessage, aWindow);
     if (aMessage.isP2P) {
       let peerImpl = new MozNFCPeerImpl(aWindow, aMessage.sessionToken);
       let peer = aWindow.MozNFCPeer._create(aWindow, peerImpl);
       aMessage.peer = peer;
     }
+
+    delete aMessage.isP2P;
+    delete aMessage.sessionToken;
+
     return aMessage;
   },
 
   classDescription: "NFCTechDiscoveredWrapper",
   classID: Components.ID("{2e7f9285-3c72-4e1f-b985-141a00a23a75}"),
   contractID: "@mozilla.org/dom/system-messages/wrapper/nfc-manager-tech-discovered;1",
   QueryInterface: XPCOMUtils.generateQI([Ci.nsISystemMessagesWrapper])
 };