diff --git a/lib/browser/guest-view-manager.js b/lib/browser/guest-view-manager.js
index c4b0022f67..de11b03206 100644
--- a/lib/browser/guest-view-manager.js
+++ b/lib/browser/guest-view-manager.js
@@ -2,6 +2,7 @@
 
 const ipcMain = require('electron').ipcMain
 const webContents = require('electron').webContents
+const parseFeaturesString = require('../common/parse-features-string')
 
 // Doesn't exist in early initialization.
 let webViewManager = null
@@ -187,27 +188,13 @@ const attachGuest = function (embedder, elementInstanceId, guestInstanceId, para
   // parse the 'webpreferences' attribute string, if set
   // this uses the same parsing rules as window.open uses for its features
   if (typeof params.webpreferences === 'string') {
-    // split the attribute's value by ','
-    let i, len
-    let webpreferencesTokens = params.webpreferences.split(/,\s*/)
-    for (i = 0, len = webpreferencesTokens.length; i < len; i++) {
-      // expected form is either a name by itself (true boolean flag)
-      // or a key/value, in the form of 'name=value'
-      // split the tokens by '='
-      let pref = webpreferencesTokens[i]
-      let prefTokens = pref.split(/\s*=/)
-      let name = prefTokens[0]
-      let value = prefTokens[1]
-      if (!name) continue
-
-      // interpret the value as a boolean, if possible 
-      value = (value === 'yes' || value === '1') ? true : (value === 'no' || value === '0') ? false : value
+    parseFeaturesString(params.webpreferences, function (key, value) {
       if (value === undefined) {
         // no value was specified, default it to true
         value = true
       }
       webPreferences[name] = value
-    }
+    })
   }
 
   if (params.preload) {
diff --git a/lib/common/parse-features-string.js b/lib/common/parse-features-string.js
new file mode 100644
index 0000000000..da0381bbcf
--- /dev/null
+++ b/lib/common/parse-features-string.js
@@ -0,0 +1,24 @@
+// parses a feature string that has the format used in window.open()
+// - `str` input string
+// - `emit` function(key, value) - called for each parsed KV
+module.exports = function parseFeaturesString (str, emit) {
+  // split the string by ','
+  let i, len
+  let strTokens = params.str.split(/,\s*/)
+  for (i = 0, len = strTokens.length; i < len; i++) {
+    // expected form is either a key by itself (true boolean flag)
+    // or a key/value, in the form of 'key=value'
+    // split the tokens by '='
+    let kv = strTokens[i]
+    let kvTokens = kv.split(/\s*=/)
+    let key = kvTokens[0]
+    let value = kvTokens[1]
+    if (!key) continue
+
+    // interpret the value as a boolean, if possible 
+    value = (value === 'yes' || value === '1') ? true : (value === 'no' || value === '0') ? false : value
+
+    // emit the parsed pair
+    emit(key, value)
+  }
+}
diff --git a/lib/renderer/override.js b/lib/renderer/override.js
index 9358a06a09..8c00661ddb 100644
--- a/lib/renderer/override.js
+++ b/lib/renderer/override.js
@@ -2,6 +2,7 @@
 
 const ipcRenderer = require('electron').ipcRenderer
 const remote = require('electron').remote
+const parseFeaturesString = require('../common/parse-features-string')
 
 // Helper function to resolve relative url.
 var a = window.top.document.createElement('a')
@@ -104,27 +105,21 @@ window.open = function (url, frameName, features) {
   // Used to store additional features
   additionalFeatures = []
 
-  // Make sure to get rid of excessive whitespace in the property name
-  ref1 = features.split(/,\s*/)
-  for (i = 0, len = ref1.length; i < len; i++) {
-    feature = ref1[i]
-    ref2 = feature.split(/\s*=/)
-    name = ref2[0]
-    value = ref2[1]
-    value = value === 'yes' || value === '1' ? true : value === 'no' || value === '0' ? false : value
+  // Parse the features
+  parseFeaturesString(features, function (key, value) {
     if (value === undefined) {
-      additionalFeatures.push(feature)
+      additionalFeatures.push(key)
     } else {
-      if (webPreferences.includes(name)) {
+      if (webPreferences.includes(key)) {
         if (options.webPreferences == null) {
           options.webPreferences = {}
         }
-        options.webPreferences[name] = value
+        options.webPreferences[key] = value
       } else {
-        options[name] = value
+        options[key] = value
       }
     }
-  }
+  })
   if (options.left) {
     if (options.x == null) {
       options.x = options.left