3 files changed, 8 insertions, 17 deletions
diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 932968fa35..a53d8efee1 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,10 @@
+*  Use Capybara registered `:puma` server config.
+
+    The Capybara registered `:puma` server ensures the puma server is run in process so
+    connection sharing and open request detection work correctly by default.
+
+    *Thomas Walpole*
+
 *  Cookies `:expires` option supports `ActiveSupport::Duration` object.
 
         cookies[:user_name] = { value: "assain", expires: 1.hour }
diff --git a/actionpack/lib/action_dispatch/system_testing/server.rb b/actionpack/lib/action_dispatch/system_testing/server.rb
index 76bada8df1..32aa6a4dc4 100644
--- a/actionpack/lib/action_dispatch/system_testing/server.rb
+++ b/actionpack/lib/action_dispatch/system_testing/server.rb
@@ -12,29 +12,17 @@ module ActionDispatch
       self.silence_puma = false
 
       def run
-        register
         setup
       end
 
       private
-        def register
-          Capybara.register_server :rails_puma do |app, port, host|
-            Rack::Handler::Puma.run(
-              app,
-              Port: port,
-              Threads: "0:1",
-              Silent: self.class.silence_puma
-            )
-          end
-        end
-
         def setup
           set_server
           set_port
         end
 
         def set_server
-          Capybara.server = :rails_puma
+          Capybara.server = :puma, { Silent: self.class.silence_puma }
         end
 
         def set_port
diff --git a/actionpack/test/dispatch/system_testing/server_test.rb b/actionpack/test/dispatch/system_testing/server_test.rb
index ed65d93e49..1866225fc1 100644
--- a/actionpack/test/dispatch/system_testing/server_test.rb
+++ b/actionpack/test/dispatch/system_testing/server_test.rb
@@ -9,10 +9,6 @@ class ServerTest < ActiveSupport::TestCase
     ActionDispatch::SystemTesting::Server.new.run
   end
 
-  test "initializing the server port" do
-    assert_includes Capybara.servers, :rails_puma
-  end
-
   test "port is always included" do
     assert Capybara.always_include_port, "expected Capybara.always_include_port to be true"
   end