diff --git a/core/phpunit.xml.dist b/core/phpunit.xml.dist
index 5bd35d3c55ca2d7dffae32f4126603df05e83633..18e1f3b3e9cb74b1d72ec0714634884d584bae4d 100644
--- a/core/phpunit.xml.dist
+++ b/core/phpunit.xml.dist
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
+<!-- For how to customize PHPUnit configuration, see core/tests/README.md. -->
 <!-- TODO set checkForUnintentionallyCoveredCode="true" once https://www.drupal.org/node/2626832 is resolved. -->
 <!-- PHPUnit expects functional tests to be run with either a privileged user
  or your current system user. See core/tests/README.md and