--- a/jekyll-sass-converter.gemspec
+++ b/jekyll-sass-converter.gemspec
@@ -13,7 +13,7 @@
   spec.homepage      = "https://github.com/jekyll/jekyll-sass-converter"
   spec.license       = "MIT"
 
-  spec.files         = `git ls-files -z`.split("\x0").grep(%r!^lib/!)
+  spec.files         = Dir["lib/**/*"]
   spec.require_paths = ["lib"]
 
   spec.required_ruby_version = ">= 2.4.0"