diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8cf322075..3a7a43f18 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,9 @@ Changes since last non-beta release.
 
 *Please add entries here for your pull requests that are not yet released.*
 
+#### Fixed
+- Fix test helper determination of stale assets. [PR 1090](https://github.com/shakacode/react_on_rails/pull/1090) by [justin808](https://github.com/justin808).
+
 #### Changed
 ### [11.0.7] - 2018-05-11
 #### Fixed
diff --git a/docs/additional-reading/rspec-configuration.md b/docs/additional-reading/rspec-configuration.md
index ee7f21b46..9ab2bdeaf 100644
--- a/docs/additional-reading/rspec-configuration.md
+++ b/docs/additional-reading/rspec-configuration.md
@@ -37,7 +37,10 @@ The following `config/react_on_rails.rb` settings **must** match your setup:
 
   # Define the files we need to check for webpack compilation when running tests.
   # Generally, the manifest.json is good enough for this check if using webpacker
-  config.webpack_generated_files = %w( hello-world-bundle.js )
+  config.webpack_generated_files = %w( manifest.json )
+  
+  # However if you're not hashing the server-bundle.js, then you should include your server-bundle.js in the list.
+  config.webpack_generated_files = %w( server-bundle.js manifest.json )
   
   # If you are using the ReactOnRails::TestHelper.configure_rspec_to_compile_assets(config)
   # with rspec then this controls what yarn command is run
diff --git a/docs/basics/configuration.md b/docs/basics/configuration.md
index 2e730a3cc..dc8569ded 100644
--- a/docs/basics/configuration.md
+++ b/docs/basics/configuration.md
@@ -58,8 +58,10 @@ ReactOnRails.configure do |config|
 
   # Define the files we need to check for webpack compilation when running tests.
   # The default is `%w( manifest.json )` as will be sufficient for most webpacker builds.
+  # However, if you are generated a server bundle that is NOT hashed (present in manifest.json),
+  # then include the file in this list like this: 
   #
-  config.webpack_generated_files = %w( manifest.json )
+  config.webpack_generated_files = %w( server-bundle.js manifest.json )
   
   # You can optionally add values to your rails_context. See example below for RenderingExtension
   # config.rendering_extension = RenderingExtension
@@ -75,8 +77,10 @@ ReactOnRails.configure do |config|
   # JavaScript execution instances which should handle any component requested.
   #
   # While you may configure this to be the same as your client bundle file, this file is typically
-  # different.
-  #
+  # different. Note, be sure to include the exact file name with the ".js" if you are not hashing this file.
+  # If you are hashing this file (supposing you are using the same file for client rendering), then
+  # 
+  # you should include a name that matches your bundle name in your webpack config.
   config.server_bundle_js_file = "server-bundle.js"
 
   # If set to true, this forces Rails to reload the server bundle if it is modified
diff --git a/docs/basics/upgrading-react-on-rails.md b/docs/basics/upgrading-react-on-rails.md
index 070ebad1e..aed1f5076 100644
--- a/docs/basics/upgrading-react-on-rails.md
+++ b/docs/basics/upgrading-react-on-rails.md
@@ -25,10 +25,10 @@ Reason for doing this: This enables your webpack bundles to bypass the Rails ass
 #### From version 7 or lower
 
 ##### ...while keeping your `client` directory
-Unfortunately, this requires quite a few steps:
 *   `.gitignore`: add `/public/webpack/*`
 *   `Gemfile`: bump `react_on_rails` and add `webpacker`
-*   layout views: anything bundled by webpack will need to be requested by a `javascript_pack_tag` or `stylesheet_pack_tag`
+*   layout views: anything bundled by webpack will need to be requested by a `javascript_pack_tag` or `stylesheet_pack_tag`. 
+  * Search your codebase for javascript_include_tag. Use the 
 *   `config/initializers/assets.rb`: we no longer need to modify `Rails.application.config.assets.paths` or append anything to `Rails.application.config.assets.precompile`.
 *   `config/initializers/react_on_rails.rb`:
     *   Delete `config.generated_assets_dir`. Webpacker's config now supplies this information
diff --git a/lib/react_on_rails/configuration.rb b/lib/react_on_rails/configuration.rb
index 942982b7f..138e5b17a 100644
--- a/lib/react_on_rails/configuration.rb
+++ b/lib/react_on_rails/configuration.rb
@@ -10,6 +10,8 @@ def self.configure
   DEFAULT_SERVER_RENDER_TIMEOUT = 20
   DEFAULT_POOL_SIZE = 1
 
+  # TODO: Move this inside of the class Configuration so as not to put all these methods
+  # on ReactOnRails
   def self.setup_config_values
     ensure_webpack_generated_files_exists
     configure_generated_assets_dirs_deprecation
diff --git a/lib/react_on_rails/prerender_error.rb b/lib/react_on_rails/prerender_error.rb
index 64a53be81..f60f20adb 100644
--- a/lib/react_on_rails/prerender_error.rb
+++ b/lib/react_on_rails/prerender_error.rb
@@ -3,6 +3,8 @@
 # rubocop:disable: Layout/IndentHeredoc
 module ReactOnRails
   class PrerenderError < ::ReactOnRails::Error
+    # TODO: Consider remove providing original `err` as already have access to `self.cause`
+    # http://blog.honeybadger.io/nested-errors-in-ruby-with-exception-cause/
     attr_reader :component_name, :err, :props, :js_code, :console_messages
 
     # err might be nil if JS caught the error
diff --git a/lib/react_on_rails/test_helper/webpack_assets_status_checker.rb b/lib/react_on_rails/test_helper/webpack_assets_status_checker.rb
index bcb0cc934..a58077300 100644
--- a/lib/react_on_rails/test_helper/webpack_assets_status_checker.rb
+++ b/lib/react_on_rails/test_helper/webpack_assets_status_checker.rb
@@ -53,7 +53,11 @@ def find_most_recent_mtime
       def all_compiled_assets
         @all_compiled_assets ||= begin
           webpack_generated_files = @webpack_generated_files.map do |bundle_name|
-            ReactOnRails::Utils.bundle_js_file_path(bundle_name)
+            if bundle_name == ReactOnRails.configuration.server_bundle_js_file
+              ReactOnRails::Utils.server_bundle_js_file_path
+            else
+              ReactOnRails::Utils.bundle_js_file_path(bundle_name)
+            end
           end
 
           if webpack_generated_files.present?
diff --git a/spec/dummy/client/webpack.client.rails.build.config.js b/spec/dummy/client/webpack.client.rails.build.config.js
index 232751ee8..170cd73bd 100644
--- a/spec/dummy/client/webpack.client.rails.build.config.js
+++ b/spec/dummy/client/webpack.client.rails.build.config.js
@@ -4,7 +4,7 @@
 
 const ExtractTextPlugin = require('extract-text-webpack-plugin');
 const merge = require('webpack-merge');
-const { env } = require('process')
+const { env } = require('process');
 const config = require('./webpack.client.base.config');
 const { resolve } = require('path');
 
@@ -14,7 +14,7 @@ const configPath = resolve('..', 'config');
 const { output, settings } = webpackConfigLoader(configPath);
 const isHMR = settings.dev_server && settings.dev_server.hmr
 
-const devBuild = process.env.NODE_ENV !== 'production';
+const devBuild = env.NODE_ENV !== 'production';
 
 
 if (devBuild) {
diff --git a/spec/react_on_rails/configuration_spec.rb b/spec/react_on_rails/configuration_spec.rb
index 4d3ec8f00..f5cf27b87 100644
--- a/spec/react_on_rails/configuration_spec.rb
+++ b/spec/react_on_rails/configuration_spec.rb
@@ -8,6 +8,10 @@ module ReactOnRails
     let(:not_existing_path) { "/path/to/#{SecureRandom.hex(4)}" }
     let(:using_webpacker) { false }
 
+    after do
+      ReactOnRails.instance_variable_set(:@configuration, nil)
+    end
+
     before do
       allow(ReactOnRails::WebpackerUtils).to receive(:using_webpacker?).and_return(using_webpacker)
     end
diff --git a/spec/react_on_rails/fixtures/webpack_assets/assets_with_manifest_exist_server_bundle_separate/client/myApp.jsx b/spec/react_on_rails/fixtures/webpack_assets/assets_with_manifest_exist_server_bundle_separate/client/myApp.jsx
new file mode 100644
index 000000000..e69de29bb
diff --git a/spec/react_on_rails/fixtures/webpack_assets/assets_with_manifest_exist_server_bundle_separate/compiled_js/client-bundle-6bc530d039d96709b68d.js b/spec/react_on_rails/fixtures/webpack_assets/assets_with_manifest_exist_server_bundle_separate/compiled_js/client-bundle-6bc530d039d96709b68d.js
new file mode 100644
index 000000000..e69de29bb
diff --git a/spec/react_on_rails/fixtures/webpack_assets/assets_with_manifest_exist_server_bundle_separate/compiled_js/manifest.json b/spec/react_on_rails/fixtures/webpack_assets/assets_with_manifest_exist_server_bundle_separate/compiled_js/manifest.json
new file mode 100644
index 000000000..5de50e317
--- /dev/null
+++ b/spec/react_on_rails/fixtures/webpack_assets/assets_with_manifest_exist_server_bundle_separate/compiled_js/manifest.json
@@ -0,0 +1,3 @@
+{
+  "client-bundle.js": "client-bundle-6bc530d039d96709b68d.js"
+}
diff --git a/spec/react_on_rails/test_helper/webpack_assets_status_checker_spec.rb b/spec/react_on_rails/test_helper/webpack_assets_status_checker_spec.rb
index c17a66de8..1973b9753 100644
--- a/spec/react_on_rails/test_helper/webpack_assets_status_checker_spec.rb
+++ b/spec/react_on_rails/test_helper/webpack_assets_status_checker_spec.rb
@@ -45,7 +45,7 @@
           .and_return(File.join(generated_assets_full_path, "client-bundle-6bc530d039d96709b68d.js"))
         allow(ReactOnRails::Utils).to receive(:bundle_js_file_path)
           .with("server-bundle.js")
-          .and_return(File.join(generated_assets_full_path, "server-bundle-6bc530d039d96702268d.js"))
+          .and_return(File.join(generated_assets_full_path, "server-bundle.js"))
         touch_files_in_dir(generated_assets_full_path)
       end
 
@@ -63,6 +63,31 @@
       specify { expect(checker.stale_generated_webpack_files).to eq(["manifest.json"]) }
     end
 
+    context "when using webpacker, a missing server bundle without hash, and manifest is current" do
+      let(:fixture_dirname) { "assets_with_manifest_exist_server_bundle_separate" }
+
+      before do
+        require "webpacker"
+        allow(ReactOnRails::WebpackerUtils).to receive(:using_webpacker?).and_return(true)
+        allow(ReactOnRails::WebpackerUtils).to receive(:manifest_exists?).and_return(true)
+        allow(ReactOnRails::WebpackerUtils).to receive(:webpacker_public_output_path)
+          .and_return(generated_assets_full_path)
+        allow(ReactOnRails.configuration).to receive(:server_bundle_js_file).and_return("server-bundle.js")
+        allow(ReactOnRails::Utils).to receive(:bundle_js_file_path)
+          .with("client-bundle.js")
+          .and_return(File.join(generated_assets_full_path, "client-bundle-6bc530d039d96709b68d.js"))
+        allow(ReactOnRails::Utils).to receive(:bundle_js_file_path)
+          .with("server-bundle.js")
+          .and_raise(Webpacker::Manifest::MissingEntryError)
+        touch_files_in_dir(generated_assets_full_path)
+      end
+
+      specify do
+        expect(checker.stale_generated_webpack_files.first)
+          .to match(/server-bundle\.js$/)
+      end
+    end
+
     context "No Webpacker" do
       before do
         allow(ReactOnRails::WebpackerUtils).to receive(:using_webpacker?).and_return(false)