diff --git a/lib/devise-kerberos-authenticatable.rb b/lib/devise-kerberos-authenticatable.rb
index 4456d2e..b11abee 100644
--- a/lib/devise-kerberos-authenticatable.rb
+++ b/lib/devise-kerberos-authenticatable.rb
@@ -6,6 +6,12 @@ require 'devise_kerberos_authenticatable/model'
 require 'devise_kerberos_authenticatable/strategy'
 require 'devise_kerberos_authenticatable/kerberos_adapter'
 
+module Devise
+  #Kerberos realm to use
+  mattr_accessor :kerberos_realm
+  @@kerberos_realm = ""
+end
+
 Devise.add_module(
   :kerberos_authenticatable,
   :strategy                   => true,
diff --git a/lib/devise_kerberos_authenticatable/kerberos_adapter.rb b/lib/devise_kerberos_authenticatable/kerberos_adapter.rb
index 6b6c536..4f5ca1a 100644
--- a/lib/devise_kerberos_authenticatable/kerberos_adapter.rb
+++ b/lib/devise_kerberos_authenticatable/kerberos_adapter.rb
@@ -9,8 +9,9 @@ module Devise
       end
 
       krb5 = Krb5.new
+      username_with_realm = "#{username}@#{::Devise.kerberos_realm}"
       begin
-        krb5.get_init_creds_password(username, password)
+        krb5.get_init_creds_password(username_with_realm, password)
       rescue Krb5Auth::Krb5::Exception
         return false
       end