diff --git a/lib/xml/rexml_ext.rb b/lib/xml/rexml_ext.rb
index a371369..9aa80cc 100644
--- a/lib/xml/rexml_ext.rb
+++ b/lib/xml/rexml_ext.rb
@@ -152,7 +152,12 @@ def each_on_axis(axis, &block)
   # temporarily suppress warnings
   class <<Kernel
     alias_method :old_warn, :warn
-    def warn(*args)
+    if RUBY_VERSION >= '2.5.0' # REXML uses additional hash parameters in ruby 2.5 and onwards
+      def warn(msg, **options)
+      end
+    else
+      def warn(msg)
+      end
     end
   end
   begin
diff --git a/xml-mapping.gemspec b/xml-mapping.gemspec
new file mode 100644
index 0000000..31627d3
--- /dev/null
+++ b/xml-mapping.gemspec
@@ -0,0 +1,32 @@
+$:.push File.expand_path('../lib', __FILE__)
+require 'xml/mapping/version'
+
+FILE_RDOC_MAIN = 'user_manual.md'.freeze
+FILES_RDOC_EXTRA = [FILE_RDOC_MAIN] + %w{README.md user_manual_xxpath.md TODO.txt doc/xpath_impl_notes.txt}
+FILES_RDOC_INCLUDES = `git ls-files examples`.split("\n").map{|f| f.gsub(/.intin.rb$/, '.intout')}
+
+Gem::Specification.new do |config|
+  config.name = 'xml-mapping'
+  config.version = XML::Mapping::VERSION
+  config.authors = ['Olaf Klischat']
+  config.email = 'olaf.klischat@gmail.com'
+  config.homepage = 'https://github.com/multi-io/xml-mapping'
+  config.summary = 'XML-Object mapper for Ruby'
+  config.description = 'An easy to use, extensible library for semi-automatically mapping Ruby objects to XML and back. Includes an XPath interpreter.'
+
+  config.rubyforge_project = 'xml-mapping'
+  config.platform = Gem::Platform::RUBY
+  config.licenses = ['Apache-2.0']
+
+
+  config.files += FILES_RDOC_EXTRA
+  config.files += FILES_RDOC_INCLUDES
+  config.files += `git ls-files lib test`.split("\n")
+  config.files += %w{LICENSE Rakefile}
+  config.test_file = 'test/all_tests.rb'
+  config.require_path = 'lib'
+  config.extra_rdoc_files = FILES_RDOC_EXTRA
+  config.rdoc_options += %w{--include examples}
+
+  config.add_development_dependency 'rake', '~> 0'
+end