diff --git a/actionpack/lib/sprockets/railtie.rb b/actionpack/lib/sprockets/railtie.rb
index 83799d2b4db22..c8438e6043349 100644
--- a/actionpack/lib/sprockets/railtie.rb
+++ b/actionpack/lib/sprockets/railtie.rb
@@ -11,15 +11,20 @@ class Railtie < ::Rails::Railtie
       load "sprockets/assets.rake"
     end
 
-    # We need to configure this after initialization to ensure we collect
-    # paths from all engines. This hook is invoked exactly before routes
-    # are compiled, and so that other Railties have an opportunity to
-    # register compressors.
-    config.after_initialize do |app|
-      assets = app.config.assets
-      next unless assets.enabled
+    initializer "sprockets.environment" do |app|
+      config = app.config
+      next unless config.assets.enabled
 
-      app.assets = asset_environment(app)
+      require 'sprockets'
+
+      app.assets = Sprockets::Environment.new(app.root.to_s) do |env|
+        env.static_root = File.join(app.root.join('public'), config.assets.prefix)
+        env.logger = ::Rails.logger
+
+        if config.assets.cache_store != false
+          env.cache = ActiveSupport::Cache.lookup_store(config.assets.cache_store) || ::Rails.cache
+        end
+      end
 
       ActiveSupport.on_load(:action_view) do
         include ::Sprockets::Helpers::RailsHelper
@@ -28,53 +33,40 @@ class Railtie < ::Rails::Railtie
           include ::Sprockets::Helpers::RailsHelper
         end
       end
-
-      app.routes.prepend do
-        mount app.assets => assets.prefix
-      end
-
-      if config.action_controller.perform_caching
-        app.assets = app.assets.index
-      end
     end
 
-    protected
-      def asset_environment(app)
-        require "sprockets"
-
-        assets = app.config.assets
-
-        env = Sprockets::Environment.new(app.root.to_s)
+    # We need to configure this after initialization to ensure we collect
+    # paths from all engines. This hook is invoked exactly before routes
+    # are compiled, and so that other Railties have an opportunity to
+    # register compressors.
+    config.after_initialize do |app|
+      next unless app.assets
+      config = app.config
 
-        env.static_root = File.join(app.root.join("public"), assets.prefix)
+      config.assets.paths.each { |path| app.assets.append_path(path) }
 
-        if env.respond_to?(:append_path)
-          assets.paths.each { |path| env.append_path(path) }
-        else
-          env.paths.concat assets.paths
+      if config.assets.compress
+        # temporarily hardcode default JS compressor to uglify. Soon, it will work
+        # the same as SCSS, where a default plugin sets the default.
+        unless config.assets.js_compressor == false
+          app.assets.js_compressor = LazyCompressor.new { expand_js_compressor(config.assets.js_compressor || :uglifier) }
         end
 
-        env.logger = ::Rails.logger
-
-        if env.respond_to?(:cache) && assets.cache_store != false
-          env.cache = ActiveSupport::Cache.lookup_store(assets.cache_store) || ::Rails.cache
+        unless config.assets.css_compressor == false
+          app.assets.css_compressor = LazyCompressor.new { expand_css_compressor(config.assets.css_compressor) }
         end
+      end
 
-        if assets.compress
-          # temporarily hardcode default JS compressor to uglify. Soon, it will work
-          # the same as SCSS, where a default plugin sets the default.
-          unless assets.js_compressor == false
-            env.js_compressor  = LazyCompressor.new { expand_js_compressor(assets.js_compressor || :uglifier) }
-          end
-
-          unless assets.css_compressor == false
-            env.css_compressor = LazyCompressor.new { expand_css_compressor(assets.css_compressor) }
-          end
-        end
+      app.routes.prepend do
+        mount app.assets => config.assets.prefix
+      end
 
-        env
+      if config.action_controller.perform_caching
+        app.assets = app.assets.index
       end
+    end
 
+    protected
       def expand_js_compressor(sym)
         case sym
         when :closure