diff --git a/Gemfile b/Gemfile
index e3fa62229..0687d8234 100644
--- a/Gemfile
+++ b/Gemfile
@@ -65,3 +65,7 @@ gem 'em-websocket'
 # code coverage
 gem 'simplecov'
 gem 'simplecov-rcov'
+
+# UI tests w/ Selenium
+gem 'selenium-webdriver'
+