2 files changed, 13 insertions, 2 deletions
diff --git a/actionpack/lib/action_dispatch/system_testing/driver.rb b/actionpack/lib/action_dispatch/system_testing/driver.rb
index 2687772b4b..280989a146 100644
--- a/actionpack/lib/action_dispatch/system_testing/driver.rb
+++ b/actionpack/lib/action_dispatch/system_testing/driver.rb
@@ -38,13 +38,24 @@ module ActionDispatch
             browser_options.args << "--disable-gpu"
 
             @options.merge(options: browser_options)
+          elsif @browser == :headless_firefox
+            browser_options = Selenium::WebDriver::Firefox::Options.new
+            browser_options.args << "-headless"
+
+            @options.merge(options: browser_options)
           else
             @options
           end
         end
 
         def browser
-          @browser == :headless_chrome ? :chrome : @browser
+          if @browser == :headless_chrome
+            :chrome
+          elsif @browser == :headless_firefox
+            :firefox
+          else
+            @browser
+          end
         end
 
         def register_selenium(app)
diff --git a/actionpack/lib/action_dispatch/system_testing/server.rb b/actionpack/lib/action_dispatch/system_testing/server.rb
index 8f1b6725b1..4fc1f33767 100644
--- a/actionpack/lib/action_dispatch/system_testing/server.rb
+++ b/actionpack/lib/action_dispatch/system_testing/server.rb
@@ -20,7 +20,7 @@ module ActionDispatch
         end
 
         def set_server
-          Capybara.server = :puma, { Silent: self.class.silence_puma }
+          Capybara.server = :puma, { Silent: self.class.silence_puma } if Capybara.server == Capybara.servers[:default]
         end
 
         def set_port