--- a/browser/modules/ContentWebRTC.jsm
+++ b/browser/modules/ContentWebRTC.jsm
@@ -154,17 +154,17 @@ function updateIndicators() {
   let state = {
     showGlobalIndicator: count > 0,
     showCameraIndicator: false,
     showMicrophoneIndicator: false,
     showScreenSharingIndicator: ""
   };
 
   for (let i = 0; i < count; ++i) {
-    let contentWindow = contentWindowSupportsArray.GetElementAt(i);
+    let contentWindow = contentWindowSupportsArray.GetElementAt(i).top;
     let camera = {}, microphone = {}, screen = {}, window = {}, app = {};
     MediaManagerService.mediaCaptureWindowState(contentWindow, camera,
                                                 microphone, screen, window, app);
     let tabState = {camera: camera.value, microphone: microphone.value};
     if (camera.value)
       state.showCameraIndicator = true;
     if (microphone.value)
       state.showMicrophoneIndicator = true;