diff --git a/actionpack/lib/action_dispatch/system_testing/driver.rb b/actionpack/lib/action_dispatch/system_testing/driver.rb
index 1fa0632fff..51cfa63e68 100644
--- a/actionpack/lib/action_dispatch/system_testing/driver.rb
+++ b/actionpack/lib/action_dispatch/system_testing/driver.rb
@@ -13,6 +13,8 @@ module ActionDispatch
           require "selenium/webdriver"
           @browser = Browser.new(options[:using])
           @browser.preload
+        else
+          @browser = nil
         end
       end