diff --git a/lib/time.gemspec b/lib/time.gemspec
index a9349a253f..4b9f9e1218 100644
--- a/lib/time.gemspec
+++ b/lib/time.gemspec
@@ -20,8 +20,12 @@ 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.split(__FILE__)
+  spec.files         = Dir.chdir(srcdir) do
+    `git ls-files -z`.split("\x0").reject { |f|
+      f == gemspec or
+        f.start_with?(".git", "bin/", "test/", "rakelib/", "Gemfile", "Rakefile")
+    }
   end
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }