diff --git a/script/gemspec b/script/gemspec
new file mode 100755
index 00000000..ca75cbfa
--- /dev/null
+++ b/script/gemspec
@@ -0,0 +1,29 @@
+#!/usr/bin/env ruby
+require File.expand_path("../ruby", __FILE__)
+
+def replace_header(head, header_name)
+  head.sub!(/(\.#{header_name}\s*= ').*'/) { "#{$1}#{MakeScript.send(header_name)}'"}
+end
+
+# read spec file and split out manifest section
+spec = File.read(MakeScript.gemspec_file)
+head, manifest, tail = spec.split("  # = MANIFEST =\n")
+
+# replace name version and date
+replace_header(head, :lib_name)
+replace_header(head, :version)
+
+files = `git ls-files`.
+  split("\n").
+  sort.
+  reject { |file| file =~ /^\./ }.
+  reject { |file| file =~ /^(rdoc|pkg)/ }.
+  map { |file| "    #{file}" }.
+  join("\n")
+
+# piece file back together and write
+manifest = "  s.files = %w[\n#{files}\n  ]\n"
+spec = [head, manifest, tail].join("  # = MANIFEST =\n")
+File.open(MakeScript.gemspec_file, 'w') { |io| io.write(spec) }
+puts "Updated #{MakeScript.gemspec_file}"
+