diff --git a/jekyll-last-modified-at.gemspec b/jekyll-last-modified-at.gemspec
index 39d85a5..48f5668 100644
--- a/jekyll-last-modified-at.gemspec
+++ b/jekyll-last-modified-at.gemspec
@@ -6,7 +6,7 @@ Gem::Specification.new do |s|
   s.authors               = "Garen J. Torikian"
   s.homepage              = "https://github.com/gjtorikian/jekyll-last-modified-at"
   s.license               = "MIT"
-  s.files                 = ["lib/**/*.rb"]
+  s.files                 = Dir["lib/**/*.rb"]
 
   s.add_dependency "jekyll"
   s.add_development_dependency "rspec", "~> 2.13.0"