diff -u a/bindata.gemspec b/bindata.gemspec
--- a/bindata.gemspec	2021-05-21 13:29:34.158562502 +0100
+++ b/bindata.gemspec	2021-05-21 13:42:00.930029375 +0100
@@ -12,7 +12,7 @@
   s.require_path = 'lib'
   s.extra_rdoc_files = ['NEWS.rdoc']
   s.rdoc_options << '--main' << 'NEWS.rdoc'
-  s.files = `git ls-files`.split("\n")
+  s.files = Dir['lib/**/*.rb'] + %w(README.md)
   s.license = 'Ruby'
 
   s.add_development_dependency('rake')