diff --git a/Gemfile.lock b/Gemfile.lock
index 6847548..b629ff7 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -40,6 +40,7 @@ GEM
       xpath (~> 0.1.4)
     childprocess (0.3.6)
       ffi (~> 1.0, >= 1.0.6)
+    crack (0.3.1)
     crypt-isaac (0.9.1)
     diff-lcs (1.1.3)
     ffi (1.1.5)
@@ -64,7 +65,8 @@ GEM
     rack-test (0.6.2)
       rack (>= 1.0)
     rake (0.8.7)
-    rb-fsevent (0.9.2)
+    rb-inotify (0.8.8)
+      ffi (>= 0.5.0)
     rspec (2.11.0)
       rspec-core (~> 2.11.0)
       rspec-expectations (~> 2.11.0)
@@ -90,6 +92,9 @@ GEM
     thor (0.16.0)
     tilt (1.3.3)
     tzinfo (0.3.33)
+    webmock (1.9.0)
+      addressable (>= 2.2.7)
+      crack (>= 0.1.7)
     xpath (0.1.4)
       nokogiri (~> 1.3)
 
@@ -103,10 +108,12 @@ DEPENDENCIES
   guard (~> 1.4.0)
   guard-rspec (= 2.0.0)
   net-ldap (~> 0.1.1)
+  nokogiri (~> 1.3)
   rack-test
   rake (= 0.8.7)
-  rb-fsevent (~> 0.9.2)
+  rb-inotify (~> 0.8.8)
   rspec
   rspec-core
   rubycas-server!
   sqlite3 (~> 1.3.1)
+  webmock (~> 1.8)
diff --git a/lib/casserver/cas.rb b/lib/casserver/cas.rb
index 0730adf..d652d21 100644
--- a/lib/casserver/cas.rb
+++ b/lib/casserver/cas.rb
@@ -247,7 +247,7 @@ module CASServer::CAS
     rand = String.random
     path = uri.path
     req = Net::HTTP::Post.new(path)
-    req.set_form_data('logoutRequest' => %{<samlp:LogoutRequest ID="#{rand}" Version="2.0" IssueInstant="#{time.rfc2822}">
+    req.set_form_data('logoutRequest' => %{<samlp:LogoutRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" ID="#{rand}" Version="2.0" IssueInstant="#{time.rfc2822}">
  <saml:NameID></saml:NameID>
  <samlp:SessionIndex>#{st.ticket}</samlp:SessionIndex>
  </samlp:LogoutRequest>})
diff --git a/rubycas-server.gemspec b/rubycas-server.gemspec
index f8f45b2..661920f 100644
--- a/rubycas-server.gemspec
+++ b/rubycas-server.gemspec
@@ -44,6 +44,8 @@ For more information on RubyCAS-Server, see http://code.google.com/p/rubycas-ser
   s.add_development_dependency("appraisal", "~> 0.4.1")
   s.add_development_dependency("guard", "~> 1.4.0")
   s.add_development_dependency("guard-rspec", "2.0.0")
+  s.add_development_dependency("webmock", "~> 1.8")
+  s.add_development_dependency("nokogiri", "~> 1.3")
 
   # pull in os specific FS monitoring lib for guard
   case RUBY_PLATFORM
diff --git a/spec/casserver/cas_spec.rb b/spec/casserver/cas_spec.rb
index 7694d2a..231b710 100644
--- a/spec/casserver/cas_spec.rb
+++ b/spec/casserver/cas_spec.rb
@@ -2,6 +2,8 @@ require 'spec_helper'
 
 module CASServer; end
 require 'casserver/cas'
+require 'nokogiri'
+require 'cgi'
 
 describe CASServer::CAS do
   before do
@@ -127,4 +129,20 @@ describe CASServer::CAS do
       @pt.ticket.should match /^PT-/
     end
   end
+
+  describe "#send_logout_notification_for_service_ticket(st)" do
+    it "should send valid single sign out XML to the service URL" do
+      service_stub = stub_request(:post, 'http://example.com')
+      st = CASServer::Model::ServiceTicket.new(
+        :ticket => 'ST-0123456789ABCDEFGHIJKLMNOPQRS',
+        :service => 'http://example.com'
+      )
+      @host.send_logout_notification_for_service_ticket(st)
+
+      a_request(:post, 'example.com').with{ |req|
+        xml = CGI.parse(req.body)['logoutRequest'].first
+        Nokogiri::XML(xml).at_xpath('//samlp:SessionIndex').text.strip == st.ticket
+      }.should have_been_made
+    end
+  end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index b91a0e0..558e9ec 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -5,6 +5,7 @@ require 'rspec'
 #require 'spec/interop/test'
 require 'logger'
 require 'ostruct'
+require 'webmock/rspec'
 
 require 'capybara'
 require 'capybara/dsl'