diff --git a/shoulda_macros/authlogic.rb b/shoulda_macros/authlogic.rb
index 53d5f04b..c81d37b6 100644
--- a/shoulda_macros/authlogic.rb
+++ b/shoulda_macros/authlogic.rb
@@ -2,7 +2,7 @@ module Authlogic
   module ShouldaMacros
     class Test::Unit::TestCase
       def self.should_be_authentic
-        klass = model_class
+        klass = described_type rescue model_class
         should "acts as authentic" do
           assert klass.new.respond_to?(:password=)
           assert klass.new.respond_to?(:valid_password?)