diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..69b1fe0
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,11 @@
+language: ruby
+rvm:
+  - 1.8.7
+  - 1.9.2
+  - 1.9.3
+  - jruby-18mode # JRuby in 1.8 mode
+  - jruby-19mode # JRuby in 1.9 mode
+  - rbx-18mode
+  - rbx-19mode
+
+script: bundle exec rspec spec
diff --git a/Gemfile.lock b/Gemfile.lock
index 1d6c8dd..42ab508 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,28 +2,23 @@ PATH
   remote: .
   specs:
     signature (0.1.2)
-      ruby-hmac
 
 GEM
   remote: http://rubygems.org/
   specs:
-    diff-lcs (1.1.2)
-    rspec (2.0.1)
-      rspec-core (~> 2.0.1)
-      rspec-expectations (~> 2.0.1)
-      rspec-mocks (~> 2.0.1)
-    rspec-core (2.0.1)
-    rspec-expectations (2.0.1)
-      diff-lcs (>= 1.1.2)
-    rspec-mocks (2.0.1)
-      rspec-core (~> 2.0.1)
-      rspec-expectations (~> 2.0.1)
-    ruby-hmac (0.4.0)
+    diff-lcs (1.1.3)
+    rspec (2.9.0)
+      rspec-core (~> 2.9.0)
+      rspec-expectations (~> 2.9.0)
+      rspec-mocks (~> 2.9.0)
+    rspec-core (2.9.0)
+    rspec-expectations (2.9.1)
+      diff-lcs (~> 1.1.3)
+    rspec-mocks (2.9.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  rspec (~> 2.0.0)
-  ruby-hmac
+  rspec (~> 2.9.0)
   signature!
diff --git a/README.md b/README.md
index 50e285a..49acf21 100644
--- a/README.md
+++ b/README.md
@@ -1,47 +1,70 @@
 signature
 =========
 
+[![Build Status](https://secure.travis-ci.org/markburns/signature.png?branch=master)](http://travis-ci.org/markburns/signature)
+
 Examples
 --------
 
 Client example
 
-    params = {:some => 'parameters'}
-    token = Signature::Token.new('my_key', 'my_secret')
-    request = Signature::Request.new('POST', '/api/thing', params)
-    auth_hash = request.sign(token)
-    query_params = params.merge(auth_hash)
-    
-    HTTParty.post('http://myservice/api/thing', {
-      :query => query_params
-    })
+```ruby
+params       = {:some => 'parameters'}
+token        = Signature::Token.new('my_key', 'my_secret')
+request      = Signature::Request.new('POST', '/api/thing', params)
+auth_hash    = request.sign(token)
+query_params = params.merge(auth_hash)
+
+HTTParty.post('http://myservice/api/thing', {
+  :query => query_params
+})
+```
 
 `query_params` looks like:
 
-    {
-      :some => "parameters",
-      :auth_timestamp => 1273231888,
-      :auth_signature => "28b6bb0f242f71064916fad6ae463fe91f5adc302222dfc02c348ae1941eaf80",
-      :auth_version => "1.0",
-      :auth_key => "my_key"
-    }
+```ruby
+{
+  :some           => "parameters",
+  :auth_timestamp => 1273231888,
+  :auth_signature => "28b6bb0f242f71064916fad6ae463fe91f5adc302222dfc02c348ae1941eaf80",
+  :auth_version   => "1.0",
+  :auth_key       => "my_key"
+}
 
+```
 Server example (sinatra)
 
-    error Signature::AuthenticationError do |controller|
-      error = controller.env["sinatra.error"]
-      halt 401, "401 UNAUTHORIZED: #{error.message}\n"
-    end
+```ruby
+error Signature::AuthenticationError do |controller|
+  error = controller.env["sinatra.error"]
+  halt 401, "401 UNAUTHORIZED: #{error.message}\n"
+end
+
+post '/api/thing' do
+  request = Signature::Request.new('POST', env["REQUEST_PATH"], params)
+  # This will raise a Signature::AuthenticationError if request does not authenticate
+  token = request.authenticate do |key|
+    Signature::Token.new(key, lookup_secret(key))
+  end
+
+  # Do whatever you need to do
+end
+```
+
+Pre-requisites
+------------
+Tested against these Ruby versions
+  * 1.8.7
+  * 1.9.2
+  * 1.9.3
+  * rbx-18mode
+  * rbx-19mode
 
-    post '/api/thing' do
-      request = Signature::Request.new('POST', env["REQUEST_PATH"], params)
-      # This will raise a Signature::AuthenticationError if request does not authenticate
-      token = request.authenticate do |key|
-        Signature::Token.new(key, lookup_secret(key))
-      end
+However JRuby currently fails with
+java.security.NoSuchAlgorithmException: sha256 MessageDigest not available
+  * jruby-18mode # JRuby in 1.8 mode
+  * jruby-19mode # JRuby in 1.9 mode
 
-      # Do whatever you need to do
-    end
 
 Developing
 ----------
diff --git a/lib/signature.rb b/lib/signature.rb
index ea62ba1..319aafc 100644
--- a/lib/signature.rb
+++ b/lib/signature.rb
@@ -1,4 +1,4 @@
-require 'hmac-sha2'
+require 'openssl'
 
 module Signature
   class AuthenticationError < RuntimeError; end
@@ -90,7 +90,11 @@ def auth_hash
     private
 
       def signature(token)
-        HMAC::SHA256.hexdigest(token.secret, string_to_sign)
+        OpenSSL::HMAC.hexdigest(digest, token.secret, string_to_sign)
+      end
+
+      def digest
+        OpenSSL::Digest::Digest.new('sha256')
       end
 
       def string_to_sign
diff --git a/signature.gemspec b/signature.gemspec
index accf999..1f757da 100644
--- a/signature.gemspec
+++ b/signature.gemspec
@@ -17,6 +17,6 @@ Gem::Specification.new do |s|
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths = ["lib"]
 
-  s.add_dependency "ruby-hmac"
-  s.add_development_dependency "rspec", "~> 2.0.0"
+  s.add_dependency "jruby-openssl" if defined?(JRUBY_VERSION)
+  s.add_development_dependency "rspec", "~> 2.9.0"
 end