diff --git a/plugins/templates/before-script.yml b/plugins/templates/before-script.yml
index 6cbeb10beb583766bd9c755f925358486fdbaa10..18bb6a829993bddbfcdfeda634e8d7a3596bb11e 100644
--- a/plugins/templates/before-script.yml
+++ b/plugins/templates/before-script.yml
@@ -13,3 +13,6 @@ before_script:
     else
       composer global require "phpunit/phpunit=4.8.*"
     fi
+
+  # PHPUnit requirements
+  - composer global require yoast/phpunit-polyfills