diff --git a/lib/shellwords.gemspec b/lib/shellwords.gemspec
index d60ab5f650..8d0c518ca5 100644
--- a/lib/shellwords.gemspec
+++ b/lib/shellwords.gemspec
@@ -21,8 +21,9 @@ Gem::Specification.new do |spec|
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage
 
-  spec.files         = Dir.chdir(File.expand_path('..', __FILE__)) do
-    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
+  srcdir, gemspec_file = File.split(__FILE__)
+  spec.files         = Dir.chdir(srcdir) do
+    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{\A(?:(?:test|spec|features)/|\.git|Rake)}) || f ==  gemspec_file}
   end
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }