3 files changed, 14 insertions, 3 deletions
diff --git a/actionview/app/assets/javascripts/README.md b/actionview/app/assets/javascripts/README.md
index 399ebc7324..f321b9f720 100644
--- a/actionview/app/assets/javascripts/README.md
+++ b/actionview/app/assets/javascripts/README.md
@@ -30,12 +30,23 @@ Run `yarn add rails-ujs` to install the rails-ujs package.
 Usage
 ------------
 
-Require `rails-ujs` into your application.js manifest.
+Require `rails-ujs` in your application.js manifest.
 
 ```javascript
 //= require rails-ujs
 ```
 
+Usage with yarn
+------------
+
+When using with the Webpacker gem or your preferred JavaScript bundler, just
+add the following to your main JS file and compile.
+
+```javascript
+import Rails from 'rails-ujs';
+Rails.start()
+```
+
 How to run tests
 ------------
 
diff --git a/actionview/app/assets/javascripts/rails-ujs/start.coffee b/actionview/app/assets/javascripts/rails-ujs/start.coffee
index 5746a22287..55595ac96f 100644
--- a/actionview/app/assets/javascripts/rails-ujs/start.coffee
+++ b/actionview/app/assets/javascripts/rails-ujs/start.coffee
@@ -9,7 +9,7 @@
 } = Rails
 
 # For backward compatibility
-if jQuery? and not jQuery.rails
+if jQuery? and jQuery.ajax? and not jQuery.rails
   jQuery.rails = Rails
   jQuery.ajaxPrefilter (options, originalOptions, xhr) ->
     CSRFProtection(xhr) unless options.crossDomain
diff --git a/actionview/app/assets/javascripts/rails-ujs/utils/ajax.coffee b/actionview/app/assets/javascripts/rails-ujs/utils/ajax.coffee
index 26df7b9a3f..a653d3af3d 100644
--- a/actionview/app/assets/javascripts/rails-ujs/utils/ajax.coffee
+++ b/actionview/app/assets/javascripts/rails-ujs/utils/ajax.coffee
@@ -14,7 +14,7 @@ AcceptHeaders =
 Rails.ajax = (options) ->
   options = prepareOptions(options)
   xhr = createXHR options, ->
-    response = processResponse(xhr.response, xhr.getResponseHeader('Content-Type'))
+    response = processResponse(xhr.response ? xhr.responseText, xhr.getResponseHeader('Content-Type'))
     if xhr.status // 100 == 2
       options.success?(response, xhr.statusText, xhr)
     else