diff --git a/README.md b/README.md
index f25ab63..74a6e10 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ However, more packages may need to be installed depending on your OS distributio
 After reviewing the dependency requirements, add `critical-path-css-rails` to your Gemfile:
 
 ```
-gem 'critical-path-css-rails', '~> 2.10.0'
+gem 'critical-path-css-rails', '~> 3.0.0'
 ```
 
 Download and install by running:
diff --git a/docker/ruby/Dockerfile b/docker/ruby/Dockerfile
index 4376437..3404a71 100644
--- a/docker/ruby/Dockerfile
+++ b/docker/ruby/Dockerfile
@@ -7,10 +7,11 @@ RUN apt-get update && apt-get install -y build-essential libpq-dev nodejs npm
 # Install Penthouse JS Dependencies
 RUN apt-get install -y libpangocairo-1.0-0 libx11-xcb1 libxcomposite1 libxcursor1 libxdamage1 libxi6 libxtst6 libnss3 libcups2 libxss1 libxrandr2 libgconf2-4 libasound2 libatk1.0-0 libgtk-3-0
 
+# Configure Node/NPM
 RUN npm cache clean -f
 RUN npm install -g n
-RUN n 8.9.3
-RUN ln -sf /usr/local/n/versions/node/8.9.3/bin/node /usr/bin/nodejs
+RUN n 10.15.1
+RUN ln -sf /usr/local/n/versions/node/10.15.1/bin/node /usr/bin/nodejs
 
 ENV BUNDLE_PATH /gems
 
diff --git a/lib/critical-path-css-rails.rb b/lib/critical-path-css-rails.rb
index 7586934..e361d3a 100644
--- a/lib/critical-path-css-rails.rb
+++ b/lib/critical-path-css-rails.rb
@@ -6,16 +6,11 @@ module CriticalPathCss
   CACHE_NAMESPACE = 'critical-path-css'.freeze
 
   def self.generate(route)
-    ::Rails.cache.write(
-      route,
-      CssFetcher.new(config).fetch_route(route),
-      namespace: CACHE_NAMESPACE,
-      expires_in: nil
-    )
+    ::Rails.cache.write(route, fetcher.fetch_route(route), namespace: CACHE_NAMESPACE, expires_in: nil)
   end
 
   def self.generate_all
-    CssFetcher.new(config).fetch.each do |route, css|
+    fetcher.fetch.each do |route, css|
       ::Rails.cache.write(route, css, namespace: CACHE_NAMESPACE, expires_in: nil)
     end
   end
@@ -32,7 +27,11 @@ def self.fetch(route)
     ::Rails.cache.read(route, namespace: CACHE_NAMESPACE) || ''
   end
 
-  def self.config
-    @config ||= Configuration.new(CriticalPathCss::Rails::ConfigLoader.new.load)
+  def self.fetcher
+    @fetcher ||= CssFetcher.new(Configuration.new(config_loader.config))
+  end
+
+  def self.config_loader
+    @config_loader ||= CriticalPathCss::Rails::ConfigLoader.new
   end
 end
diff --git a/lib/critical_path_css/css_fetcher.rb b/lib/critical_path_css/css_fetcher.rb
index 3ead1a2..54a9880 100644
--- a/lib/critical_path_css/css_fetcher.rb
+++ b/lib/critical_path_css/css_fetcher.rb
@@ -10,33 +10,21 @@ def initialize(config)
     end
 
     def fetch
-      @config.routes.map.with_index { |route, index|
-        css_path = @config.css_paths[index].present? ? @config.css_paths[index] : @config.css_path
-        [route, css_for_route(route, css_path)]
-      }.to_h
+      @config.routes.map { |route| [route, fetch_route(route)] }.to_h
     end
 
     def fetch_route(route)
-      css_for_route route
-    end
-
-    protected
-
-    def css_for_route(route, css_path)
       options = {
         'url' => @config.base_url + route,
-        'css' => css_path,
-        ## optional params
-        # viewport dimensions
+        'css' => fetch_css_path_for_route(route),
         'width' => 1300,
         'height' => 900,
+        'timeout' => 30_000,
         # CSS selectors to always include, e.g.:
         'forceInclude' => [
           #  '.keepMeEvenIfNotSeenInDom',
           #  '^\.regexWorksToo'
         ],
-        # ms; abort critical CSS generation after this timeout
-        'timeout' => 30_000,
         # set to true to throw on CSS errors (will run faster if no errors)
         'strict' => false,
         # characters; strip out inline base64 encoded resources larger than this
@@ -63,5 +51,17 @@ def css_for_route(route, css_path)
       end
       out
     end
+
+    private
+
+    def fetch_css_path_for_route(route)
+      index_for_route = @config.routes.index(route)
+
+      if index_for_route && @config.css_paths[index_for_route]
+        @config.css_paths[index_for_route]
+      else
+        @config.css_path
+      end
+    end
   end
 end
diff --git a/lib/critical_path_css/rails/config_loader.rb b/lib/critical_path_css/rails/config_loader.rb
index ee4d00d..27f1d8a 100644
--- a/lib/critical_path_css/rails/config_loader.rb
+++ b/lib/critical_path_css/rails/config_loader.rb
@@ -3,22 +3,13 @@ module Rails
     class ConfigLoader
       CONFIGURATION_FILENAME = 'critical_path_css.yml'.freeze
 
-      def load
-        config = YAML.safe_load(ERB.new(File.read(configuration_file_path)).result, [], [], true)[::Rails.env]
-        validate_css_path config
-        if config['css_path']
-          config['css_path'] = "#{::Rails.root}/public" + (
-            config['css_path'] ||
-              ActionController::Base.helpers.stylesheet_path(
-                config['manifest_name'], host: ''
-              )
-          )
-          config['css_paths'] = []
-        else
-          config['css_path'] = ''
-          config['css_paths'] = config['css_paths'].collect { |path| "#{::Rails.root}/public#{path}" }
-        end
-        config
+      def initialize
+        validate_css_paths
+        format_css_paths
+      end
+
+      def config
+        @config ||= YAML.safe_load(ERB.new(File.read(configuration_file_path)).result, [], [], true)[::Rails.env]
       end
 
       private
@@ -27,7 +18,21 @@ def configuration_file_path
         @configuration_file_path ||= ::Rails.root.join('config', CONFIGURATION_FILENAME)
       end
 
-      def validate_css_path(config)
+      def format_css_paths
+        if config['css_path']
+          config['css_path']  = format_path(config['css_path'])
+          config['css_paths'] = []
+        else
+          config['css_path']  = ''
+          config['css_paths'] = config['css_paths'].collect { |path| format_path(path) }
+        end
+      end
+
+      def format_path(path)
+        "#{::Rails.root}/public#{path}"
+      end
+
+      def validate_css_paths
         if config['css_path'] && config['css_paths']
           raise LoadError, 'Cannot specify both css_path and css_paths'
         elsif config['css_paths'] && config['css_paths'].length != config['routes'].length
diff --git a/package-lock.json b/package-lock.json
index a3e7120..bc55893 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,7 +9,7 @@
       "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-4.2.1.tgz",
       "integrity": "sha512-JVwXMr9nHYTUXsBFKUqhJwvlcYU/blreOEUkhNR2eXZIvwd+c+o5V4MgDPKWnMS/56awN3TRzIP+KoPn+roQtg==",
       "requires": {
-        "es6-promisify": "5.0.0"
+        "es6-promisify": "^5.0.0"
       }
     },
     "async-limiter": {
@@ -27,7 +27,7 @@
       "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
       "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
       "requires": {
-        "balanced-match": "1.0.0",
+        "balanced-match": "^1.0.0",
         "concat-map": "0.0.1"
       }
     },
@@ -46,10 +46,10 @@
       "resolved": "https://registry.npmjs.org/concat-stream/-/concat-stream-1.6.2.tgz",
       "integrity": "sha512-27HBghJxjiZtIk3Ycvn/4kbJk/1uZuJFfuPEns6LaEvpvG1f0hTea8lilrouyo9mVc2GWdcEZ8OLoGmSADlrCw==",
       "requires": {
-        "buffer-from": "1.1.1",
-        "inherits": "2.0.3",
-        "readable-stream": "2.3.6",
-        "typedarray": "0.0.6"
+        "buffer-from": "^1.0.0",
+        "inherits": "^2.0.3",
+        "readable-stream": "^2.2.2",
+        "typedarray": "^0.0.6"
       }
     },
     "core-util-is": {
@@ -67,8 +67,8 @@
       "resolved": "https://registry.npmjs.org/css-tree/-/css-tree-1.0.0-alpha.28.tgz",
       "integrity": "sha512-joNNW1gCp3qFFzj4St6zk+Wh/NBv0vM5YbEreZk0SD4S23S+1xBKb6cLDg2uj4P4k/GUMlIm6cKIDqIG+vdt0w==",
       "requires": {
-        "mdn-data": "1.1.4",
-        "source-map": "0.5.7"
+        "mdn-data": "~1.1.0",
+        "source-map": "^0.5.3"
       }
     },
     "debug": {
@@ -76,7 +76,7 @@
       "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.0.tgz",
       "integrity": "sha512-heNPJUJIqC+xB6ayLAMHaIrmN9HKa7aQO8MGqKpvCA+uJYVcvR6l5kgdrhRuwPFHU7P5/A1w0BjByPHwpfTDKg==",
       "requires": {
-        "ms": "2.1.1"
+        "ms": "^2.1.1"
       }
     },
     "es6-promise": {
@@ -86,10 +86,10 @@
     },
     "es6-promisify": {
       "version": "5.0.0",
-      "resolved": "http://registry.npmjs.org/es6-promisify/-/es6-promisify-5.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/es6-promisify/-/es6-promisify-5.0.0.tgz",
       "integrity": "sha1-UQnWLz5W6pZ8S2NQWu8IKRyKUgM=",
       "requires": {
-        "es6-promise": "4.2.5"
+        "es6-promise": "^4.0.3"
       }
     },
     "extract-zip": {
@@ -123,7 +123,7 @@
       "resolved": "https://registry.npmjs.org/fd-slicer/-/fd-slicer-1.0.1.tgz",
       "integrity": "sha1-i1vL2ewyfFBBv5qwI/1nUPEXfmU=",
       "requires": {
-        "pend": "1.2.0"
+        "pend": "~1.2.0"
       }
     },
     "fs.realpath": {
@@ -136,12 +136,12 @@
       "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.3.tgz",
       "integrity": "sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==",
       "requires": {
-        "fs.realpath": "1.0.0",
-        "inflight": "1.0.6",
-        "inherits": "2.0.3",
-        "minimatch": "3.0.4",
-        "once": "1.4.0",
-        "path-is-absolute": "1.0.1"
+        "fs.realpath": "^1.0.0",
+        "inflight": "^1.0.4",
+        "inherits": "2",
+        "minimatch": "^3.0.4",
+        "once": "^1.3.0",
+        "path-is-absolute": "^1.0.0"
       }
     },
     "https-proxy-agent": {
@@ -149,8 +149,8 @@
       "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-2.2.1.tgz",
       "integrity": "sha512-HPCTS1LW51bcyMYbxUIOO4HEOlQ1/1qRaFWcyxvwaqUS9TY88aoEuHUY33kuAh1YhVVaDQhLZsnPd+XNARWZlQ==",
       "requires": {
-        "agent-base": "4.2.1",
-        "debug": "3.2.6"
+        "agent-base": "^4.1.0",
+        "debug": "^3.1.0"
       },
       "dependencies": {
         "debug": {
@@ -158,7 +158,7 @@
           "resolved": "https://registry.npmjs.org/debug/-/debug-3.2.6.tgz",
           "integrity": "sha512-mel+jf7nrtEl5Pn1Qx46zARXKDpBbvzezse7p7LqINmdoIk8PYP5SySaxEmYv6TZ0JyEKA1hsCId6DIhgITtWQ==",
           "requires": {
-            "ms": "2.1.1"
+            "ms": "^2.1.1"
           }
         }
       }
@@ -168,8 +168,8 @@
       "resolved": "https://registry.npmjs.org/inflight/-/inflight-1.0.6.tgz",
       "integrity": "sha1-Sb1jMdfQLQwJvJEKEHW6gWW1bfk=",
       "requires": {
-        "once": "1.4.0",
-        "wrappy": "1.0.2"
+        "once": "^1.3.0",
+        "wrappy": "1"
       }
     },
     "inherits": {
@@ -202,17 +202,17 @@
       "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
       "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
       "requires": {
-        "brace-expansion": "1.1.11"
+        "brace-expansion": "^1.1.7"
       }
     },
     "minimist": {
       "version": "0.0.8",
-      "resolved": "http://registry.npmjs.org/minimist/-/minimist-0.0.8.tgz",
+      "resolved": "https://registry.npmjs.org/minimist/-/minimist-0.0.8.tgz",
       "integrity": "sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0="
     },
     "mkdirp": {
       "version": "0.5.1",
-      "resolved": "http://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz",
+      "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz",
       "integrity": "sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=",
       "requires": {
         "minimist": "0.0.8"
@@ -228,7 +228,7 @@
       "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
       "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
       "requires": {
-        "wrappy": "1.0.2"
+        "wrappy": "1"
       }
     },
     "path-is-absolute": {
@@ -246,10 +246,10 @@
       "resolved": "https://registry.npmjs.org/penthouse/-/penthouse-1.10.1.tgz",
       "integrity": "sha512-D0fUazt6EvtoJvbKJ4u6yVIwfrWoSW1+2clr5JZaKag5pzgwLJKYcN8NgmAoBmWOwsMk+3ZAkV5Cv09LzQtqAw==",
       "requires": {
-        "css-mediaquery": "0.1.2",
+        "css-mediaquery": "^0.1.2",
         "css-tree": "1.0.0-alpha.28",
-        "debug": "4.1.0",
-        "jsesc": "2.5.1",
+        "debug": "^4.1.0",
+        "jsesc": "^2.5.1",
         "puppeteer": "1.9.0"
       }
     },
@@ -273,14 +273,14 @@
       "resolved": "https://registry.npmjs.org/puppeteer/-/puppeteer-1.9.0.tgz",
       "integrity": "sha512-GH4PmhJf9wBRAPvtJkEJLAvdNNOofZortmBZSj8cGWYni98GUFqsf66blOEfJbo5B8l0KG5HR2d/W2MejnUrzg==",
       "requires": {
-        "debug": "3.2.6",
-        "extract-zip": "1.6.7",
-        "https-proxy-agent": "2.2.1",
-        "mime": "2.3.1",
-        "progress": "2.0.1",
-        "proxy-from-env": "1.0.0",
-        "rimraf": "2.6.2",
-        "ws": "5.2.2"
+        "debug": "^3.1.0",
+        "extract-zip": "^1.6.6",
+        "https-proxy-agent": "^2.2.1",
+        "mime": "^2.0.3",
+        "progress": "^2.0.0",
+        "proxy-from-env": "^1.0.0",
+        "rimraf": "^2.6.1",
+        "ws": "^5.1.1"
       },
       "dependencies": {
         "debug": {
@@ -288,23 +288,23 @@
           "resolved": "https://registry.npmjs.org/debug/-/debug-3.2.6.tgz",
           "integrity": "sha512-mel+jf7nrtEl5Pn1Qx46zARXKDpBbvzezse7p7LqINmdoIk8PYP5SySaxEmYv6TZ0JyEKA1hsCId6DIhgITtWQ==",
           "requires": {
-            "ms": "2.1.1"
+            "ms": "^2.1.1"
           }
         }
       }
     },
     "readable-stream": {
       "version": "2.3.6",
-      "resolved": "http://registry.npmjs.org/readable-stream/-/readable-stream-2.3.6.tgz",
+      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-2.3.6.tgz",
       "integrity": "sha512-tQtKA9WIAhBF3+VLAseyMqZeBjW0AHJoxOtYqSUZNJxauErmLbVm2FW1y+J/YA9dUrAC39ITejlZWhVIwawkKw==",
       "requires": {
-        "core-util-is": "1.0.2",
-        "inherits": "2.0.3",
-        "isarray": "1.0.0",
-        "process-nextick-args": "2.0.0",
-        "safe-buffer": "5.1.2",
-        "string_decoder": "1.1.1",
-        "util-deprecate": "1.0.2"
+        "core-util-is": "~1.0.0",
+        "inherits": "~2.0.3",
+        "isarray": "~1.0.0",
+        "process-nextick-args": "~2.0.0",
+        "safe-buffer": "~5.1.1",
+        "string_decoder": "~1.1.1",
+        "util-deprecate": "~1.0.1"
       }
     },
     "rimraf": {
@@ -312,7 +312,7 @@
       "resolved": "https://registry.npmjs.org/rimraf/-/rimraf-2.6.2.tgz",
       "integrity": "sha512-lreewLK/BlghmxtfH36YYVg1i8IAce4TI7oao75I1g245+6BctqTVQiBP3YUJ9C6DQOXJmkYR9X9fCLtCOJc5w==",
       "requires": {
-        "glob": "7.1.3"
+        "glob": "^7.0.5"
       }
     },
     "safe-buffer": {
@@ -330,7 +330,7 @@
       "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.1.1.tgz",
       "integrity": "sha512-n/ShnvDi6FHbbVfviro+WojiFzv+s8MPMHBczVePfUpDJLwoLT0ht1l4YwBCbi8pJAveEEdnkHyPyTP/mzRfwg==",
       "requires": {
-        "safe-buffer": "5.1.2"
+        "safe-buffer": "~5.1.0"
       }
     },
     "typedarray": {
@@ -353,7 +353,7 @@
       "resolved": "https://registry.npmjs.org/ws/-/ws-5.2.2.tgz",
       "integrity": "sha512-jaHFD6PFv6UgoIVda6qZllptQsMlDEJkTQcybzzXDYM1XO9Y8em691FGMPmM46WGyLU4z9KMgQN+qrux/nhlHA==",
       "requires": {
-        "async-limiter": "1.0.0"
+        "async-limiter": "~1.0.0"
       }
     },
     "yauzl": {
@@ -361,7 +361,7 @@
       "resolved": "https://registry.npmjs.org/yauzl/-/yauzl-2.4.1.tgz",
       "integrity": "sha1-lSj0QtqxsihOWLQ3m7GU4i4MQAU=",
       "requires": {
-        "fd-slicer": "1.0.1"
+        "fd-slicer": "~1.0.1"
       }
     }
   }
diff --git a/spec/lib/critical_path_css/css_fetcher_spec.rb b/spec/lib/critical_path_css/css_fetcher_spec.rb
index 86e4d89..32b0cd9 100644
--- a/spec/lib/critical_path_css/css_fetcher_spec.rb
+++ b/spec/lib/critical_path_css/css_fetcher_spec.rb
@@ -1,22 +1,36 @@
 require 'spec_helper'
 
 RSpec.describe 'CssFetcher' do
-  describe '#fetch' do
-    let(:subject) { CriticalPathCss::CssFetcher.new(config) }
-    let(:response) {
-      ['foo','', OpenStruct.new(exitstatus: 0)]
-    }
-    let(:routes) { ['/', '/new_route'] }
-    let(:config) do
-      OpenStruct.new(
-        base_url: 'http://0.0.0.0:9292',
-        css_path: css_path,
-        css_paths: css_paths,
-        penthouse_options: {},
-        routes: routes
-      )
+  let(:subject) { CriticalPathCss::CssFetcher.new(config) }
+  let(:response) { ['foo','', OpenStruct.new(exitstatus: 0)] }
+  let(:routes) { ['/', '/new_route'] }
+  let(:config) do
+    OpenStruct.new(
+      base_url: 'http://0.0.0.0:9292',
+      css_path: css_path,
+      css_paths: css_paths,
+      penthouse_options: {},
+      routes: routes
+    )
+  end
+
+  describe '#fetch_route' do
+    context 'when a single css_path is configured' do
+      let(:css_path) { '/test.css' }
+      let(:css_paths) { [] }
+
+      it 'generates css for the single route' do
+        expect(Open3).to receive(:capture3) do |arg1, arg2, arg3|
+          options = JSON.parse(arg3)
+          expect(options['css']).to eq '/test.css'
+        end.once.and_return(response)
+
+        subject.fetch_route(routes.first)
+      end
     end
+  end
 
+  describe '#fetch' do
     context 'when a single css_path is configured' do
       let(:css_path) { '/test.css' }
       let(:css_paths) { [] }
diff --git a/spec/lib/critical_path_css/rails/config_loader_spec.rb b/spec/lib/critical_path_css/rails/config_loader_spec.rb
index 232b7ab..d6fbfae 100644
--- a/spec/lib/critical_path_css/rails/config_loader_spec.rb
+++ b/spec/lib/critical_path_css/rails/config_loader_spec.rb
@@ -2,6 +2,7 @@
 
 RSpec.describe 'ConfigLoader' do
   let(:subject) { CriticalPathCss::Rails::ConfigLoader.new }
+
   describe '#load' do
     before do
       allow(File).to receive(:read).and_return(config_file)
@@ -25,15 +26,11 @@
       }
 
       it 'sets css_path with the path' do
-        config = subject.load
-
-        expect(config['css_path']).to eq '/app/spec/internal/public/test.css'
+        expect(subject.config['css_path']).to eq '/app/spec/internal/public/test.css'
       end
 
       it 'leaves css_paths empty' do
-        config = subject.load
-
-        expect(config['css_paths']).to eq []
+        expect(subject.config['css_paths']).to eq []
       end
     end
 
@@ -58,15 +55,11 @@
       }
 
       it 'sets css_path to empty string' do
-        config = subject.load
-
-        expect(config['css_path']).to eq ''
+        expect(subject.config['css_path']).to eq ''
       end
 
       it 'leaves css_paths to an array of paths' do
-        config = subject.load
-
-        expect(config['css_paths']).to eq ['/app/spec/internal/public/test.css','/app/spec/internal/public/test2.css']
+        expect(subject.config['css_paths']).to eq ['/app/spec/internal/public/test.css','/app/spec/internal/public/test2.css']
       end
     end
 
@@ -92,7 +85,7 @@
       }
 
       it 'raises an error' do
-        expect { subject.load }.to raise_error LoadError, 'Cannot specify both css_path and css_paths'
+        expect { subject }.to raise_error LoadError, 'Cannot specify both css_path and css_paths'
       end
     end
 
@@ -118,7 +111,7 @@
       }
 
       it 'raises an error' do
-        expect { subject.load }.to raise_error LoadError, 'Must specify css_paths for each route'
+        expect { subject }.to raise_error LoadError, 'Must specify css_paths for each route'
       end
     end
   end