diff --git a/lib/validates_timeliness/helper_methods.rb b/lib/validates_timeliness/helper_methods.rb
index 122dfe3..107ede6 100644
--- a/lib/validates_timeliness/helper_methods.rb
+++ b/lib/validates_timeliness/helper_methods.rb
@@ -14,8 +14,16 @@ module ActiveModel
         timeliness_validation_for attr_names, :datetime
       end
 
-      def timeliness_validation_for(attr_names, type)
-        validates_with TimelinessValidator, _merge_attributes(attr_names).merge(:type => type)
+      def validates_timeliness_of(*attr_names)
+        timeliness_validation_for attr_names
+      end
+
+      def timeliness_validation_for(attr_names, type=nil)
+        options = _merge_attributes(attr_names)
+        options.update(:type => type) if type
+        # Rails 4.0 and 4.1 compatibility for old #setup method with class as arg
+        options.update(:class => self) unless options.has_key?(:class)
+        validates_with TimelinessValidator, _merge_attributes(attr_names)
       end
     end
 
diff --git a/lib/validates_timeliness/validator.rb b/lib/validates_timeliness/validator.rb
index 806dbe2..651f503 100644
--- a/lib/validates_timeliness/validator.rb
+++ b/lib/validates_timeliness/validator.rb
@@ -5,7 +5,7 @@ module ValidatesTimeliness
   class Validator < ActiveModel::EachValidator
     include Conversion
 
-    attr_reader :type
+    attr_reader :type, :attributes
 
     RESTRICTIONS = {
       :is_at        => :==,
@@ -42,13 +42,14 @@ module ValidatesTimeliness
       end
 
       @restrictions_to_check = RESTRICTIONS.keys & options.keys
-      super
-    end
 
-    def setup(model)
+      super
+
+      model = options[:class]
+
       if model.respond_to?(:timeliness_validated_attributes)
         model.timeliness_validated_attributes ||= []
-        model.timeliness_validated_attributes |= @attributes
+        model.timeliness_validated_attributes |= attributes
       end
     end