diff --git a/core/phpunit.xml.dist b/core/phpunit.xml.dist
index 963d921a7e..2a55d680f3 100644
--- a/core/phpunit.xml.dist
+++ b/core/phpunit.xml.dist
@@ -30,8 +30,10 @@
     <env name="BROWSERTEST_OUTPUT_DIRECTORY" value=""/>
     <!-- To disable deprecation testing uncomment the next line. -->
     <env name="SYMFONY_DEPRECATIONS_HELPER" value="weak_vendors"/>
+    <!-- Example for changing the driver class for mink tests MINK_DRIVER_CLASS value: 'Drupal\FunctionalJavascriptTests\DrupalSelenium2Driver' -->
     <!-- Example for changing the driver args to mink tests MINK_DRIVER_ARGS value: '["http://127.0.0.1:8510"]' -->
     <!-- Example for changing the driver args to phantomjs tests MINK_DRIVER_ARGS_PHANTOMJS value: '["http://127.0.0.1:8510"]' -->
+    <!-- Example for changing the driver args to webdriver tests MINK_DRIVER_ARGS_WEBDRIVER value: '["firefox", null, "http://localhost:4444/wd/hub"]' -->
   </php>
   <testsuites>
     <testsuite name="unit">
diff --git a/core/tests/README.md b/core/tests/README.md
index ea42929058..fcaa5cc2c2 100644
--- a/core/tests/README.md
+++ b/core/tests/README.md
@@ -40,7 +40,7 @@ For help installing and starting selenium, see http://mink.behat.org/en/latest/d
 
 * Make sure you have a recent version of chrome installed
 
-* Perform the required installs
+* Install selenium-server-standalone and chromedriver
 
 Example for Mac:
 
@@ -60,13 +60,20 @@ export MINK_DRIVER_ARGS_WEBDRIVER='["chrome", null, "http://localhost:4444/wd/hu
 ./vendor/bin/phpunit -c core --testsuite functional-javascript
 ```
 
-* Set an additional environment parameter to tell the test to use firefox:
+* It is possible to use alternate browsers if the required dependencies are
+installed. For example to use Firefox:
+
 ```
-export MINK_DRIVER_ARGS='["firefox", null, "http://localhost:4444/wd/hub"]'
+export MINK_DRIVER_ARGS_WEBDRIVER='["firefox", null, "http://localhost:4444/wd/hub"]'
+./vendor/bin/phpunit -c core --testsuite functional-javascript
 ```
-* Run the tests as before, now a firefox window should appear.
+
+* To force all BrowserTestBase (including legacy JavascriptTestBase) tests to use
+webdriver:
+
 ```
-  ./vendor/bin/phpunit -c core --testsuite functional-javascript
+export MINK_DRIVER_CLASS='Drupal\FunctionalJavascriptTests\DrupalSelenium2Driver'
+./vendor/bin/phpunit -c core --testsuite functional-javascript
 ```
 
 ## Running legacy javascript tests