--- a/posix-spawn.gemspec
+++ b/posix-spawn.gemspec
@@ -17,9 +17,7 @@
   s.add_development_dependency 'minitest', '>= 4'
 
   s.extensions = ['ext/extconf.rb']
-  s.executables << 'posix-spawn-benchmark'
   s.require_paths = ['lib']
 
-  s.files = `git ls-files`.split("\n")
-  s.extra_rdoc_files = %w[ COPYING HACKING ]
+  s.files = Dir['lib/**/*', 'ext/*']
 end