diff --git a/test/helper.rb b/test/helper.rb
index 64f7db7e2..32456fde4 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -28,7 +28,7 @@ class TaskManager
     include Rake::TaskManager
   end
 
-  RUBY = File.realpath(ENV["BUNDLE_RUBY"] || Gem.ruby)
+  RUBY = File.realpath(ENV["RUBY"] || Gem.ruby)
 
   def setup
     ARGV.clear