diff --git a/lib/browser/guest-window-manager.js b/lib/browser/guest-window-manager.js
index c3767ad8c6..78c9158f8e 100644
--- a/lib/browser/guest-window-manager.js
+++ b/lib/browser/guest-window-manager.js
@@ -1,7 +1,6 @@
 'use strict'
 
-const ipcMain = require('electron').ipcMain
-const BrowserWindow = require('electron').BrowserWindow
+const {BrowserWindow, ipcMain, webContents} = require('electron')
 
 const hasProp = {}.hasOwnProperty
 const frameToGuest = {}
@@ -56,15 +55,14 @@ const createGuest = function (embedder, url, frameName, options) {
   if (options.webPreferences == null) {
     options.webPreferences = {}
   }
-  const embedderWindow = BrowserWindow.fromWebContents(embedder)
-  options.webPreferences.openerId = embedderWindow != null ? embedderWindow.id : void 0
+  options.webPreferences.openerId = embedder.id
   guest = new BrowserWindow(options)
   guest.loadURL(url)
 
   // When |embedder| is destroyed we should also destroy attached guest, and if
   // guest is closed by user then we should prevent |embedder| from double
   // closing guest.
-  const guestId = guest.id
+  const guestId = guest.webContents.id
 
   const closedByEmbedder = function () {
     guest.removeListener('closed', closedByUser)
@@ -85,7 +83,18 @@ const createGuest = function (embedder, url, frameName, options) {
     })
   }
 
-  return guest.id
+  return guestId
+}
+
+const getGuestWindow = function (guestId) {
+  const guestContents = webContents.fromId(guestId)
+  if (guestContents == null) return
+
+  let guestWindow = BrowserWindow.fromWebContents(guestContents)
+  if (guestWindow == null && guestContents.hostWebContents != null) {
+    guestWindow = BrowserWindow.fromWebContents(guestContents.hostWebContents)
+  }
+  return guestWindow
 }
 
 // Routed window.open messages.
@@ -100,35 +109,26 @@ ipcMain.on('ELECTRON_GUEST_WINDOW_MANAGER_WINDOW_OPEN', function (event, url, fr
 })
 
 ipcMain.on('ELECTRON_GUEST_WINDOW_MANAGER_WINDOW_CLOSE', function (event, guestId) {
-  const guestWindow = BrowserWindow.fromId(guestId)
+  const guestWindow = getGuestWindow(guestId)
   if (guestWindow != null) guestWindow.destroy()
 })
 
 ipcMain.on('ELECTRON_GUEST_WINDOW_MANAGER_WINDOW_METHOD', function (event, guestId, method, ...args) {
-  const guestWindow = BrowserWindow.fromId(guestId)
-  event.returnValue = guestWindow != null ? guestWindow[method].apply(guestWindow, args) : void 0
+  const guestWindow = getGuestWindow(guestId)
+  event.returnValue = guestWindow != null ? guestWindow[method].apply(guestWindow, args) : null
 })
 
 ipcMain.on('ELECTRON_GUEST_WINDOW_MANAGER_WINDOW_POSTMESSAGE', function (event, guestId, message, targetOrigin, sourceOrigin) {
-  const sourceContents = BrowserWindow.fromWebContents(event.sender)
-  const sourceId = sourceContents != null ? sourceContents.id : void 0
-  if (sourceId == null) {
-    return
-  }
+  const guestContents = webContents.fromId(guestId)
+  if (guestContents == null) return
 
-  const guestWindow = BrowserWindow.fromId(guestId)
-  const guestContents = guestWindow != null ? guestWindow.webContents : void 0
-  if ((guestContents != null ? guestContents.getURL().indexOf(targetOrigin) : void 0) === 0 || targetOrigin === '*') {
-    guestContents != null ? guestContents.send('ELECTRON_GUEST_WINDOW_POSTMESSAGE', sourceId, message, sourceOrigin) : void 0
+  if (guestContents.getURL().indexOf(targetOrigin) === 0 || targetOrigin === '*') {
+    const sourceId = event.sender.id
+    guestContents.send('ELECTRON_GUEST_WINDOW_POSTMESSAGE', sourceId, message, sourceOrigin)
   }
 })
 
 ipcMain.on('ELECTRON_GUEST_WINDOW_MANAGER_WEB_CONTENTS_METHOD', function (event, guestId, method, ...args) {
-  const guestWindow = BrowserWindow.fromId(guestId)
-  if (guestWindow != null) {
-    const guestContents = guestWindow.webContents
-    if (guestContents != null) {
-      guestContents[method].apply(guestContents, args)
-    }
-  }
+  const guestContents = webContents.fromId(guestId)
+  if (guestContents != null) guestContents[method].apply(guestContents, args)
 })