diff --git a/concourse/tasks/rake-test/run.sh b/concourse/tasks/rake-test/run.sh
index 89c7cb4f..8b751200 100755
--- a/concourse/tasks/rake-test/run.sh
+++ b/concourse/tasks/rake-test/run.sh
@@ -4,6 +4,7 @@ set -e -x -u
 
 pushd loofah
 
+  export RUBYOPT="--enable-frozen-string-literal --debug=frozen-string-literal"
   bundle install
   bundle exec rake test