diff --git a/docs/tutorial/security.md b/docs/tutorial/security.md
index f8d4123d4b3a..1ab7608217df 100644
--- a/docs/tutorial/security.md
+++ b/docs/tutorial/security.md
@@ -511,7 +511,7 @@ no circumstances should you enable features speculatively.
 // Bad
 const mainWindow = new BrowserWindow({
   webPreferences: {
-    enableBlinkFeatures: ['ExecCommandInJavaScript']
+    enableBlinkFeatures: 'ExecCommandInJavaScript'
   }
 })
 ```
diff --git a/spec-main/security-warnings-spec.ts b/spec-main/security-warnings-spec.ts
new file mode 100644
index 000000000000..a44dc52fe955
--- /dev/null
+++ b/spec-main/security-warnings-spec.ts
@@ -0,0 +1,235 @@
+import { expect } from 'chai'
+import * as http from 'http'
+import * as fs from 'fs'
+import * as path from 'path'
+import * as url from 'url'
+
+import { BrowserWindow, WebPreferences } from 'electron'
+
+import { closeWindow } from './window-helpers'
+import { AddressInfo } from 'net';
+import { emittedOnce } from './events-helpers';
+
+describe('security warnings', () => {
+  let server: http.Server
+  let w: BrowserWindow
+  let useCsp = true
+  let serverUrl: string
+
+  before((done) => {
+    // Create HTTP Server
+    server = http.createServer((request, response) => {
+      const uri = url.parse(request.url!).pathname!
+      let filename = path.join(__dirname, '..', 'spec', 'fixtures', 'pages', uri)
+
+      fs.stat(filename, (error, stats) => {
+        if (error) {
+          response.writeHead(404, { 'Content-Type': 'text/plain' })
+          response.end()
+          return
+        }
+
+        if (stats.isDirectory()) {
+          filename += '/index.html'
+        }
+
+        fs.readFile(filename, 'binary', (err, file) => {
+          if (err) {
+            response.writeHead(404, { 'Content-Type': 'text/plain' })
+            response.end()
+            return
+          }
+
+          const cspHeaders = { 'Content-Security-Policy': `script-src 'self' 'unsafe-inline'` }
+          response.writeHead(200, useCsp ? cspHeaders : undefined)
+          response.write(file, 'binary')
+          response.end()
+        })
+      })
+    }).listen(0, '127.0.0.1', () => {
+      serverUrl = `http://127.0.0.1:${(server.address() as AddressInfo).port}`
+      done()
+    })
+  })
+
+  after(() => {
+    // Close server
+    server.close()
+    server = null as unknown as any
+  })
+
+  afterEach(async () => {
+    useCsp = true
+    await closeWindow(w)
+    w = null as unknown as any
+  })
+
+  it('should warn about Node.js integration with remote content', async () => {
+    w = new BrowserWindow({
+      show: false,
+      webPreferences: {
+        nodeIntegration: true
+      }
+    })
+
+    w.loadURL(`${serverUrl}/base-page-security.html`)
+    const [,, message] = await emittedOnce(w.webContents, 'console-message')
+    expect(message).to.include('Node.js Integration with Remote Content')
+  })
+
+  it('should not warn about Node.js integration with remote content from localhost', (done) => {
+    w = new BrowserWindow({
+      show: false,
+      webPreferences: {
+        nodeIntegration: true
+      }
+    })
+    w.webContents.once('console-message', (e, level, message) => {
+      expect(message).to.not.include('Node.js Integration with Remote Content')
+
+      if (message === 'loaded') {
+        done()
+      }
+    })
+
+    w.loadURL(`${serverUrl}/base-page-security-onload-message.html`)
+  })
+
+  const generateSpecs = (description: string, webPreferences: WebPreferences) => {
+    describe(description, () => {
+      it('should warn about disabled webSecurity', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences: {
+            webSecurity: false,
+            ...webPreferences
+          }
+        })
+
+        w.loadURL(`${serverUrl}/base-page-security.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('Disabled webSecurity')
+      })
+
+      it('should warn about insecure Content-Security-Policy', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences: {
+            enableRemoteModule: false,
+            ...webPreferences
+          }
+        })
+
+        useCsp = false
+        w.loadURL(`${serverUrl}/base-page-security.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('Insecure Content-Security-Policy')
+      })
+
+      it('should warn about allowRunningInsecureContent', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences: {
+            allowRunningInsecureContent: true,
+            ...webPreferences
+          }
+        })
+
+        w.loadURL(`${serverUrl}/base-page-security.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('allowRunningInsecureContent')
+      })
+
+      it('should warn about experimentalFeatures', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences: {
+            experimentalFeatures: true,
+            ...webPreferences
+          }
+        })
+
+        w.loadURL(`${serverUrl}/base-page-security.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('experimentalFeatures')
+      })
+
+      it('should warn about enableBlinkFeatures', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences: {
+            enableBlinkFeatures: 'my-cool-feature',
+            ...webPreferences
+          }
+        })
+
+        w.loadURL(`${serverUrl}/base-page-security.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('enableBlinkFeatures')
+      })
+
+      it('should warn about allowpopups', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences
+        })
+
+        w.loadURL(`${serverUrl}/webview-allowpopups.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('allowpopups')
+      })
+
+      it('should warn about insecure resources', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences: { ...webPreferences }
+        })
+
+        w.loadURL(`${serverUrl}/insecure-resources.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('Insecure Resources')
+      })
+
+      it('should not warn about loading insecure-resources.html from localhost', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences
+        })
+
+        w.loadURL(`${serverUrl}/insecure-resources.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.not.include('insecure-resources.html')
+      })
+
+      it('should warn about enabled remote module with remote content', async () => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences
+        })
+
+        w.loadURL(`${serverUrl}/base-page-security.html`)
+        const [,, message] = await emittedOnce(w.webContents, 'console-message')
+        expect(message).to.include('enableRemoteModule')
+      })
+
+      it('should not warn about enabled remote module with remote content from localhost', (done) => {
+        w = new BrowserWindow({
+          show: false,
+          webPreferences
+        })
+        w.webContents.once('console-message', (e, level, message) => {
+          expect(message).to.not.include('enableRemoteModule')
+
+          if (message === 'loaded') {
+            done()
+          }
+        })
+
+        w.loadURL(`${serverUrl}/base-page-security-onload-message.html`)
+      })
+    })
+  }
+
+  generateSpecs('without sandbox', {})
+  generateSpecs('with sandbox', { sandbox: true })
+})
diff --git a/spec/fixtures/pages/insecure-resources.html b/spec/fixtures/pages/insecure-resources.html
index 97f91b769eae..105911325383 100644
--- a/spec/fixtures/pages/insecure-resources.html
+++ b/spec/fixtures/pages/insecure-resources.html
@@ -1,6 +1,6 @@
 <html>
   <head>
-    <link rel="stylesheet" href="http://127.0.0.1:8881/save_page/test.css">
+    <link rel="stylesheet" href="/save_page/test.css">
     <script type="text/javascript">
       window.ELECTRON_ENABLE_SECURITY_WARNINGS = true
     </script>
diff --git a/spec/security-warnings-spec.js b/spec/security-warnings-spec.js
deleted file mode 100644
index 45141b4dd966..000000000000
--- a/spec/security-warnings-spec.js
+++ /dev/null
@@ -1,257 +0,0 @@
-const chai = require('chai')
-const dirtyChai = require('dirty-chai')
-
-const http = require('http')
-const fs = require('fs')
-const path = require('path')
-const url = require('url')
-
-const { remote } = require('electron')
-const { BrowserWindow } = remote
-
-const { closeWindow } = require('./window-helpers')
-
-const { expect } = chai
-chai.use(dirtyChai)
-
-describe('security warnings', () => {
-  let server
-  let w = null
-  let useCsp = true
-
-  before((done) => {
-    // Create HTTP Server
-    server = http.createServer((request, response) => {
-      const uri = url.parse(request.url).pathname
-      let filename = path.join(__dirname, './fixtures/pages', uri)
-
-      fs.stat(filename, (error, stats) => {
-        if (error) {
-          response.writeHead(404, { 'Content-Type': 'text/plain' })
-          response.end()
-          return
-        }
-
-        if (stats.isDirectory()) {
-          filename += '/index.html'
-        }
-
-        fs.readFile(filename, 'binary', (err, file) => {
-          if (err) {
-            response.writeHead(404, { 'Content-Type': 'text/plain' })
-            response.end()
-            return
-          }
-
-          const cspHeaders = { 'Content-Security-Policy': `script-src 'self' 'unsafe-inline'` }
-          response.writeHead(200, useCsp ? cspHeaders : undefined)
-          response.write(file, 'binary')
-          response.end()
-        })
-      })
-    }).listen(8881, () => done())
-  })
-
-  after(() => {
-    // Close server
-    server.close()
-    server = null
-  })
-
-  afterEach(() => {
-    useCsp = true
-    return closeWindow(w).then(() => { w = null })
-  })
-
-  it('should warn about Node.js integration with remote content', (done) => {
-    w = new BrowserWindow({
-      show: false,
-      webPreferences: {
-        nodeIntegration: true
-      }
-    })
-    w.webContents.once('console-message', (e, level, message) => {
-      expect(message).to.include('Node.js Integration with Remote Content')
-      done()
-    })
-
-    w.loadURL(`http://127.0.0.1:8881/base-page-security.html`)
-  })
-
-  it('should not warn about Node.js integration with remote content from localhost', (done) => {
-    w = new BrowserWindow({
-      show: false,
-      webPreferences: {
-        nodeIntegration: true
-      }
-    })
-    w.webContents.once('console-message', (e, level, message) => {
-      expect(message).to.not.include('Node.js Integration with Remote Content')
-
-      if (message === 'loaded') {
-        done()
-      }
-    })
-
-    w.loadURL(`http://localhost:8881/base-page-security-onload-message.html`)
-  })
-
-  const generateSpecs = (description, webPreferences) => {
-    describe(description, () => {
-      it('should warn about disabled webSecurity', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences: {
-            webSecurity: false,
-            ...webPreferences
-          }
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('Disabled webSecurity')
-          done()
-        })
-
-        w.loadURL(`http://127.0.0.1:8881/base-page-security.html`)
-      })
-
-      it('should warn about insecure Content-Security-Policy', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences: {
-            enableRemoteModule: false,
-            ...webPreferences
-          }
-        })
-
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('Insecure Content-Security-Policy')
-          done()
-        })
-
-        useCsp = false
-        w.loadURL(`http://127.0.0.1:8881/base-page-security.html`)
-      })
-
-      it('should warn about allowRunningInsecureContent', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences: {
-            allowRunningInsecureContent: true,
-            ...webPreferences
-          }
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('allowRunningInsecureContent')
-          done()
-        })
-
-        w.loadURL(`http://127.0.0.1:8881/base-page-security.html`)
-      })
-
-      it('should warn about experimentalFeatures', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences: {
-            experimentalFeatures: true,
-            ...webPreferences
-          }
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('experimentalFeatures')
-          done()
-        })
-
-        w.loadURL(`http://127.0.0.1:8881/base-page-security.html`)
-      })
-
-      it('should warn about enableBlinkFeatures', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences: {
-            enableBlinkFeatures: ['my-cool-feature'],
-            ...webPreferences
-          }
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('enableBlinkFeatures')
-          done()
-        })
-
-        w.loadURL(`http://127.0.0.1:8881/base-page-security.html`)
-      })
-
-      it('should warn about allowpopups', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('allowpopups')
-          done()
-        })
-
-        w.loadURL(`http://127.0.0.1:8881/webview-allowpopups.html`)
-      })
-
-      it('should warn about insecure resources', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('Insecure Resources')
-          done()
-        })
-
-        w.loadURL(`http://127.0.0.1:8881/insecure-resources.html`)
-        w.webContents.openDevTools()
-      })
-
-      it('should not warn about loading insecure-resources.html from localhost', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.not.include('insecure-resources.html')
-          done()
-        })
-
-        w.loadURL(`http://localhost:8881/insecure-resources.html`)
-        w.webContents.openDevTools()
-      })
-
-      it('should warn about enabled remote module with remote content', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.include('enableRemoteModule')
-          done()
-        })
-
-        w.loadURL(`http://127.0.0.1:8881/base-page-security.html`)
-      })
-
-      it('should not warn about enabled remote module with remote content from localhost', (done) => {
-        w = new BrowserWindow({
-          show: false,
-          webPreferences
-        })
-        w.webContents.once('console-message', (e, level, message) => {
-          expect(message).to.not.include('enableRemoteModule')
-
-          if (message === 'loaded') {
-            done()
-          }
-        })
-
-        w.loadURL(`http://localhost:8881/base-page-security-onload-message.html`)
-      })
-    })
-  }
-
-  generateSpecs('without sandbox', {})
-  generateSpecs('with sandbox', { sandbox: true })
-})