diff --git a/test/net/http/utils.rb b/test/net/http/utils.rb
index 0b9e440..f499963 100644
--- a/test/net/http/utils.rb
+++ b/test/net/http/utils.rb
@@ -26,14 +26,14 @@ def initialize(config, &block)
     def start
       @thread = Thread.new do
         loop do
-          socket = (@ssl_server || @server).accept
+          socket = server.accept
           run(socket)
         rescue
         ensure
           socket&.close
         end
       ensure
-        (@ssl_server || @server).close
+        server.close
       end
     end
 
@@ -44,6 +44,7 @@ def run(socket)
     def shutdown
       @thread&.kill
       @thread&.join
+      server&.close
     end
 
     def mount(path, proc)
@@ -94,6 +95,10 @@ def port
       @port
     end
 
+    private def server
+      @ssl_server || @server
+    end
+
     class Request
       attr_reader :method, :path, :headers, :query, :body
       def initialize(method, path, headers, socket)