--- a/net-smtp.gemspec
+++ b/net-smtp.gemspec
@@ -25,3 +25 @@
-  spec.files = Dir.chdir(File.expand_path('..', __FILE__)) do
-    `git ls-files README.md NEWS.md LICENSE.txt net-smtp.gemspec lib`.split
-  end
+  spec.files = Dir["lib/**/*.rb"]