core/phpunit.xml.dist | 7 +++++++
 core/tests/README.md  | 7 +++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/core/phpunit.xml.dist b/core/phpunit.xml.dist
index 951bd55..b9f7d69 100644
--- a/core/phpunit.xml.dist
+++ b/core/phpunit.xml.dist
@@ -1,4 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+ This is an example file.
+
+ 1. Copy this to core/phpunit.xml.
+ 2. Modify the base URL & DB values.
+ 3. Now you can run all tests.
+-->
 
 <!-- TODO set checkForUnintentionallyCoveredCode="true" once https://www.drupal.org/node/2626832 is resolved. -->
 <!-- TODO set printerClass="\Drupal\Tests\Listeners\HtmlOutputPrinter" once
diff --git a/core/tests/README.md b/core/tests/README.md
index dfd1154..84662e1 100644
--- a/core/tests/README.md
+++ b/core/tests/README.md
@@ -1,15 +1,18 @@
 # Running tests
 
+Copy `core/phpunit.xml.dist` to `core/phpunit.xml` and modify it:
+- specify a value for SIMPLETEST_BASE_URL (to let PHPUnit know your site's URL)
+- specify a value for SIMPLETEST_DB (to let PHPUnit know your DB credentials)
+
 ## Functional tests
 
 * Start PhantomJS:
   ```
   phantomjs --ssl-protocol=any --ignore-ssl-errors=true ./vendor/jcalderonzumba/gastonjs/src/Client/main.js 8510 1024 768 2>&1 >> /dev/null &
   ```
+  (This will keep PhantomJS running in the background.)
 * Run the functional tests:
   ```
-  export SIMPLETEST_DB='mysql://root@localhost/dev_d8'
-  export SIMPLETEST_BASE_URL='http://d8.dev'
   ./vendor/bin/phpunit -c core --testsuite functional
   ./vendor/bin/phpunit -c core --testsuite functional-javascript
   ```