diff --git a/features/support/env.rb b/features/support/env.rb
index 525f8596da30c2520b007064abeacd2ef1c2ea9f..c0d3be812180ad6db2315e1ef9149b526669f5f4 100644
--- a/features/support/env.rb
+++ b/features/support/env.rb
@@ -15,6 +15,12 @@ require 'capybara/session'
 # Ensure we know the appservers port
 Capybara.server_port = 9887
 
+# Use a version of Firefox defined by environment variable, if set
+Capybara.register_driver :selenium do |app|
+  require 'selenium/webdriver'
+  Selenium::WebDriver::Firefox::Binary.path = ENV['FIREFOX_BINARY_PATH'] || Selenium::WebDriver::Firefox::Binary.path
+  Capybara::Selenium::Driver.new(app, :browser => :firefox)
+end
 
 # Capybara defaults to XPath selectors rather than Webrat's default of CSS3. In
 # order to ease the transition to Capybara we set the default here. If you'd