diff --git a/docs/guides/testing/testing.rst b/docs/guides/testing/testing.rst
index ee488b4fb2..bf02801325 100644
--- a/docs/guides/testing/testing.rst
+++ b/docs/guides/testing/testing.rst
@@ -236,6 +236,8 @@ If you run into flakiness, check (and feel free to contribute to) this
 Running Javascript Unit Tests
 -----------------------------
 
+Before running Javascript unit tests, you will need to be running Firefox or Chrome in a place visible to edx-platform. If running this in devstack, you can run ``make dev.up.firefox`` or ``make dev.up.chrome``. Firefox is the default browser for the tests, so if you decide to use Chrome, you will need to prefix the test command with ``SELENIUM_BROWSER=chrome SELENIUM_HOST=edx.devstack.chrome`` (if using devstack).
+
 We use Jasmine to run JavaScript unit tests. To run all the JavaScript
 tests::