--- a/nkf.gemspec
+++ b/nkf.gemspec
@@ -27,4 +27 @@
-  # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
-  spec.files         = Dir.chdir(File.expand_path('..', __FILE__)) do
-    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
-  end
+  spec.files         = Dir["ext/nkf/**/*", "lib/**/*.rb"]