diff --git a/test/support/circleci.rb b/test/support/circleci.rb
index 5a36bfa..18de4b4 100644
--- a/test/support/circleci.rb
+++ b/test/support/circleci.rb
@@ -1,6 +1,6 @@
 # Generate XML test reports that can be parsed by CircleCI
-if ENV["CIRCLECI"]
+if ENV['CIRCLECI']
   require 'minitest/ci'
 
-  Minitest::Ci.report_dir = "#{ENV["CIRCLE_TEST_REPORTS"]}/reports"
+  Minitest::Ci.report_dir = File.join(ENV.fetch('CIRCLE_TEST_REPORTS'), 'reports')
 end