diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3df8a6ea11..9d7e88c3d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## TBD
+- (plugin-network-breadcrumbs): Fixes the `window.fetch` monkey-patch to also accept `Request`. [#662](https://github.com/bugsnag/bugsnag-js/pull/662)
+
 ## 6.4.3 (2019-10-21)
 
 ### Fixed
diff --git a/packages/plugin-network-breadcrumbs/network-breadcrumbs.js b/packages/plugin-network-breadcrumbs/network-breadcrumbs.js
index 1915b05ec2..e20836074a 100644
--- a/packages/plugin-network-breadcrumbs/network-breadcrumbs.js
+++ b/packages/plugin-network-breadcrumbs/network-breadcrumbs.js
@@ -119,15 +119,34 @@ const monkeyPatchFetch = () => {
   if (!('fetch' in win) || win.fetch.polyfill) return
 
   const oldFetch = win.fetch
-  win.fetch = function fetch (...args) {
-    let [url, options] = args
-    let method = 'GET'
-    if (options && options.method) {
-      method = options.method
+  win.fetch = function fetch () {
+    const urlOrRequest = arguments[0]
+    const options = arguments[1]
+
+    let method
+    let url = null
+
+    if (urlOrRequest && typeof urlOrRequest === 'object') {
+      url = urlOrRequest.url
+      if (options && 'method' in options) {
+        method = options.method
+      } else if (urlOrRequest && 'method' in urlOrRequest) {
+        method = urlOrRequest.method
+      }
+    } else {
+      url = urlOrRequest
+      if (options && 'method' in options) {
+        method = options.method
+      }
     }
+
+    if (method === undefined) {
+      method = 'GET'
+    }
+
     return new Promise((resolve, reject) => {
       // pass through to native fetch
-      oldFetch(...args)
+      oldFetch(...arguments)
         .then(response => {
           handleFetchSuccess(response, method, url)
           resolve(response)
diff --git a/packages/plugin-network-breadcrumbs/test/network-breadcrumbs.test.js b/packages/plugin-network-breadcrumbs/test/network-breadcrumbs.test.js
index 9b7074daf6..e3fb7e35bb 100644
--- a/packages/plugin-network-breadcrumbs/test/network-breadcrumbs.test.js
+++ b/packages/plugin-network-breadcrumbs/test/network-breadcrumbs.test.js
@@ -27,6 +27,7 @@ XMLHttpRequest.prototype.removeEventListener = function (evt, listener) {
   if (listener === this._listeners[evt]) delete this._listeners[evt]
 }
 
+// mock fetch
 function fetch (url, options, fail, status) {
   return new Promise((resolve, reject) => {
     if (fail) {
@@ -37,6 +38,12 @@ function fetch (url, options, fail, status) {
   })
 }
 
+// mock (fetch) Request
+function Request (url, opts) {
+  this.url = url
+  this.method = (opts && opts.method) || 'GET'
+}
+
 describe('plugin: network breadcrumbs', () => {
   afterEach(() => {
     // undo the global side effects
@@ -179,6 +186,208 @@ describe('plugin: network breadcrumbs', () => {
     })
   })
 
+  it('should handle a fetch(url, { method: null })', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    window.fetch('/', { method: null }, false, 405).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() failed',
+        metaData: {
+          status: 405,
+          request: 'null /'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle a fetch() request supplied with a Request object', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    const request = new Request('/')
+
+    window.fetch(request, {}, false, 200).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() succeeded',
+        metaData: {
+          status: 200,
+          request: 'GET /'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle a fetch() request supplied with a Request object that has a method specified', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    const request = new Request('/', { method: 'PUT' })
+
+    window.fetch(request, {}, false, 200).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() succeeded',
+        metaData: {
+          status: 200,
+          request: 'PUT /'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle fetch(null)', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    window.fetch(null, {}, false, 404).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() failed',
+        metaData: {
+          status: 404,
+          request: 'GET null'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle fetch(url, null)', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    window.fetch('/', null, false, 200).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() succeeded',
+        metaData: {
+          status: 200,
+          request: 'GET /'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle fetch(undefined)', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    window.fetch(undefined, {}, false, 404).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() failed',
+        metaData: {
+          status: 404,
+          request: 'GET undefined'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle a fetch(request, { method })', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    window.fetch(new Request('/foo', { method: 'GET' }), { method: 'PUT' }, false, 200).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() succeeded',
+        metaData: {
+          status: 200,
+          request: 'PUT /foo'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle a fetch(request, { method: null })', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    window.fetch(new Request('/foo'), { method: null }, false, 405).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() failed',
+        metaData: {
+          status: 405,
+          request: 'null /foo'
+        }
+      }))
+      done()
+    })
+  })
+
+  it('should handle a fetch(request, { method: undefined })', (done) => {
+    const window = { XMLHttpRequest, fetch }
+
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'aaaa-aaaa-aaaa-aaaa' })
+    client.configure()
+    client.use(plugin, () => [], window)
+
+    window.fetch(new Request('/foo'), { method: undefined }, false, 200).then(() => {
+      expect(client.breadcrumbs.length).toBe(1)
+      expect(client.breadcrumbs[0]).toEqual(jasmine.objectContaining({
+        type: 'request',
+        name: 'fetch() succeeded',
+        metaData: {
+          status: 200,
+          request: 'GET /foo'
+        }
+      }))
+      done()
+    })
+  })
+
   it('should leave a breadcrumb when a fetch() has a failed response', (done) => {
     const window = { XMLHttpRequest, fetch }