diff --git a/tool/lib/webrick/webrick.gemspec b/tool/lib/webrick/webrick.gemspec
deleted file mode 100644
index 5ede24d7ec..0000000000
--- a/tool/lib/webrick/webrick.gemspec
+++ /dev/null
@@ -1,76 +0,0 @@
-# frozen_string_literal: true
-begin
-  require_relative 'lib/webrick/version'
-rescue LoadError
-  # for Ruby core repository
-  require_relative 'version'
-end
-
-Gem::Specification.new do |s|
-  s.name = "webrick"
-  s.version = WEBrick::VERSION
-  s.summary = "HTTP server toolkit"
-  s.description = "WEBrick is an HTTP server toolkit that can be configured as an HTTPS server, a proxy server, and a virtual-host server."
-
-  s.require_path = %w{lib}
-  s.files =  [
-    "Gemfile",
-    "LICENSE.txt",
-    "README.md",
-    "Rakefile",
-    "bin/console",
-    "bin/setup",
-    "lib/webrick.rb",
-    "lib/webrick/accesslog.rb",
-    "lib/webrick/cgi.rb",
-    "lib/webrick/compat.rb",
-    "lib/webrick/config.rb",
-    "lib/webrick/cookie.rb",
-    "lib/webrick/htmlutils.rb",
-    "lib/webrick/httpauth.rb",
-    "lib/webrick/httpauth/authenticator.rb",
-    "lib/webrick/httpauth/basicauth.rb",
-    "lib/webrick/httpauth/digestauth.rb",
-    "lib/webrick/httpauth/htdigest.rb",
-    "lib/webrick/httpauth/htgroup.rb",
-    "lib/webrick/httpauth/htpasswd.rb",
-    "lib/webrick/httpauth/userdb.rb",
-    "lib/webrick/httpproxy.rb",
-    "lib/webrick/httprequest.rb",
-    "lib/webrick/httpresponse.rb",
-    "lib/webrick/https.rb",
-    "lib/webrick/httpserver.rb",
-    "lib/webrick/httpservlet.rb",
-    "lib/webrick/httpservlet/abstract.rb",
-    "lib/webrick/httpservlet/cgi_runner.rb",
-    "lib/webrick/httpservlet/cgihandler.rb",
-    "lib/webrick/httpservlet/erbhandler.rb",
-    "lib/webrick/httpservlet/filehandler.rb",
-    "lib/webrick/httpservlet/prochandler.rb",
-    "lib/webrick/httpstatus.rb",
-    "lib/webrick/httputils.rb",
-    "lib/webrick/httpversion.rb",
-    "lib/webrick/log.rb",
-    "lib/webrick/server.rb",
-    "lib/webrick/ssl.rb",
-    "lib/webrick/utils.rb",
-    "lib/webrick/version.rb",
-    "webrick.gemspec",
-  ]
-  s.required_ruby_version = ">= 2.3.0"
-
-  s.authors = ["TAKAHASHI Masayoshi", "GOTOU YUUZOU", "Eric Wong"]
-  s.email = [nil, nil, 'normal@ruby-lang.org']
-  s.homepage = "https://www.ruby-lang.org"
-  s.licenses = ["Ruby", "BSD-2-Clause"]
-
-  if s.respond_to?(:metadata=)
-    s.metadata = {
-      "bug_tracker_uri" => "https://bugs.ruby-lang.org/projects/ruby-master/issues",
-      "homepage_uri" => "https://www.ruby-lang.org",
-      "source_code_uri" => "https://git.ruby-lang.org/ruby.git/"
-    }
-  end
-
-  s.add_development_dependency "rake"
-end