diff --git a/bin/sdoc b/bin/sdoc
index 78640fee..1cdbd854 100755
--- a/bin/sdoc
+++ b/bin/sdoc
@@ -1,6 +1,11 @@
 #!/usr/bin/env ruby -KU
 require 'sdoc'
 
+if ARGV.include?("--version")
+  puts "sdoc #{SDoc::VERSION}"
+  exit 0
+end
+
 begin
   ARGV.push('--format=sdoc') if ARGV.grep(/\A(-f|--fmt|--format|-r|-R|--ri|--ri-site)\b/).empty?
   r = RDoc::RDoc.new
diff --git a/lib/sdoc.rb b/lib/sdoc.rb
index 8aef0116..eeefa23c 100644
--- a/lib/sdoc.rb
+++ b/lib/sdoc.rb
@@ -2,6 +2,8 @@
 require "rubygems"
 gem 'rdoc'
 
-module SDoc end
+module SDoc
+  VERSION = '0.4.0.rc.1'
+end
 
 require 'sdoc/generator'
diff --git a/sdoc.gemspec b/sdoc.gemspec
index 9664e702..bae88101 100644
--- a/sdoc.gemspec
+++ b/sdoc.gemspec
@@ -1,8 +1,9 @@
 # -*- encoding: utf-8 -*-
+require_relative 'lib/sdoc.rb'
 
 Gem::Specification.new do |s|
   s.name = "sdoc"
-  s.version = "0.4.0.rc.1"
+  s.version = SDoc::VERSION
 
   s.authors = ["Vladimir Kolesnikov", "Nathan Broadbent", "Jean Mertz", "Zachary Scott"]
   s.description = %q{rdoc generator html with javascript search index.}