diff --git a/test/helper.rb b/test/helper.rb
index 949b63520..29f81c1f6 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -26,7 +26,7 @@ class TaskManager
     include Rake::TaskManager
   end
 
-  RUBY = ENV['BUNDLE_RUBY'] || Gem.ruby
+  RUBY = ENV["BUNDLE_RUBY"] || Gem.ruby
 
   def setup
     ARGV.clear