diff --git a/lib/ember_cli.rb b/lib/ember_cli.rb
index a097bffcee6..a14efc9299e 100644
--- a/lib/ember_cli.rb
+++ b/lib/ember_cli.rb
@@ -9,7 +9,7 @@ class EmberCli < ActiveSupport::CurrentAttributes
   end
 
   def self.assets
-    cache[:assets] ||= Dir.glob("**/*.{js,map,txt}", base: "#{dist_dir}/assets")
+    cache[:assets] ||= Dir.glob("**/*.{js,map,txt,css}", base: "#{dist_dir}/assets")
   end
 
   def self.script_chunks