diff --git a/dom/network/src/NetworkStatsManager.js b/dom/network/src/NetworkStatsManager.js
index a2ce59a910b1..9731a0bc60ae 100644
--- a/dom/network/src/NetworkStatsManager.js
+++ b/dom/network/src/NetworkStatsManager.js
@@ -43,24 +43,19 @@ NetworkStatsData.prototype = {
 };
 
 // NetworkStatsInterface
-const NETWORKSTATSINTERFACE_CONTRACTID = "@mozilla.org/networkstatsinterface;1";
 const NETWORKSTATSINTERFACE_CID = Components.ID("{f540615b-d803-43ff-8200-2a9d145a5645}");
 
-function NetworkStatsInterface() {
+function NetworkStatsInterface(aNetwork) {
   if (DEBUG) {
     debug("NetworkStatsInterface Constructor");
   }
+  this.type = aNetwork.type;
+  this.id = aNetwork.id;
 }
 
 NetworkStatsInterface.prototype = {
-  __init: function(aNetwork) {
-    this.type = aNetwork.type;
-    this.id = aNetwork.id;
-  },
-
   classID : NETWORKSTATSINTERFACE_CID,
 
-  contractID: NETWORKSTATSINTERFACE_CONTRACTID,
   QueryInterface : XPCOMUtils.generateQI([])
 }
 
@@ -73,7 +68,8 @@ function NetworkStats(aWindow, aStats) {
   }
   this.appManifestURL = aStats.appManifestURL || null;
   this.serviceType = aStats.serviceType || null;
-  this.network = new aWindow.MozNetworkStatsInterface(aStats.network);
+  this.network = aWindow.MozNetworkStatsInterface._create(
+    aWindow, new NetworkStatsInterface(aStats.network));
   this.start = aStats.start ? new aWindow.Date(aStats.start.getTime()) : null;
   this.end = aStats.end ? new aWindow.Date(aStats.end.getTime()) : null;
 
@@ -95,7 +91,8 @@ const NETWORKSTATSALARM_CID = Components.ID("{a93ea13e-409c-4189-9b1e-95fff220be
 
 function NetworkStatsAlarm(aWindow, aAlarm) {
   this.alarmId = aAlarm.id;
-  this.network = new aWindow.MozNetworkStatsInterface(aAlarm.network);
+  this.network = aWindow.MozNetworkStatsInterface._create(
+    aWindow, new NetworkStatsInterface(aAlarm.network));
   this.threshold = aAlarm.threshold;
   this.data = aAlarm.data;
 }
@@ -310,7 +307,8 @@ NetworkStatsManager.prototype = {
 
         let networks = new this._window.Array();
         for (let i = 0; i < msg.result.length; i++) {
-          let network = new this._window.MozNetworkStatsInterface(msg.result[i]);
+          let network = this._window.MozNetworkStatsInterface._create(
+            this._window, new NetworkStatsInterface(msg.result[i]));
           networks.push(network);
         }
 
diff --git a/dom/network/tests/test_networkstats_alarms.html b/dom/network/tests/test_networkstats_alarms.html
index a7952b65da45..e0f801fee8bf 100644
--- a/dom/network/tests/test_networkstats_alarms.html
+++ b/dom/network/tests/test_networkstats_alarms.html
@@ -40,8 +40,7 @@ var steps = [
   function () {
     ok(true, "Calling getAllAlarms() with invalid network.");
 
-    req = navigator.mozNetworkStats
-                   .getAllAlarms(new window.MozNetworkStatsInterface(mobile));
+    req = navigator.mozNetworkStats.getAllAlarms(mobile);
 
     req.onsuccess = function () {
       ok(false, "getAllAlarms() shouldn't succeed!");
@@ -70,14 +69,13 @@ var steps = [
     }
 
     try {
-      navigator.mozNetworkStats.addAlarm(new window.MozNetworkStatsInterface(wifi));
+      navigator.mozNetworkStats.addAlarm(wifi);
     } catch(ex) {
       ok(ex.result == SpecialPowers.Cr.NS_ERROR_XPC_NOT_ENOUGH_ARGS,
          "addAlarm() throws NS_ERROR_XPC_NOT_ENOUGH_ARGS exception when no threshold");
     }
 
-    req = navigator.mozNetworkStats
-                   .addAlarm(new window.MozNetworkStatsInterface(mobile), -100000);
+    req = navigator.mozNetworkStats.addAlarm(mobile, -100000);
 
     req.onsuccess = function () {
       ok(false, "addAlarm() shouldn't succeed with negative threshold.");
@@ -91,8 +89,7 @@ var steps = [
   function () {
     ok(true, "Calling addAlarm()");
 
-    req = navigator.mozNetworkStats
-                   .addAlarm(new window.MozNetworkStatsInterface(wifi), 1000000);
+    req = navigator.mozNetworkStats.addAlarm(wifi, 1000000);
 
     req.onsuccess = function () {
       ok(true, "Succeeded to add alarm. AlarmId: " + req.result);
@@ -105,8 +102,7 @@ var steps = [
   function () {
     ok(true, "Calling getAllAlarms()");
 
-    req = navigator.mozNetworkStats
-                   .getAllAlarms(new window.MozNetworkStatsInterface(wifi));
+    req = navigator.mozNetworkStats.getAllAlarms(wifi);
 
     req.onsuccess = function () {
       ok(req.result.length == 1, "Only one alarm");
diff --git a/dom/webidl/MozNetworkStatsInterface.webidl b/dom/webidl/MozNetworkStatsInterface.webidl
index 8221ab962cb6..775c131a6a6a 100644
--- a/dom/webidl/MozNetworkStatsInterface.webidl
+++ b/dom/webidl/MozNetworkStatsInterface.webidl
@@ -2,16 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-dictionary NetworkInterface {
-  long type;
-  DOMString id;
-};
-
 /**
  * Represents a data interface for which the manager is recording statistics.
  */
-[Constructor(optional NetworkInterface networkinterface),
- JSImplementation="@mozilla.org/networkstatsinterface;1",
+[JSImplementation="@mozilla.org/networkstatsinterface;1",
+ ChromeOnly,
  Pref="dom.mozNetworkStats.enabled",
  Func="Navigator::HasNetworkStatsSupport"]
 interface MozNetworkStatsInterface {