diff --git a/lib/validates_timeliness/helper_methods.rb b/lib/validates_timeliness/helper_methods.rb
index d5d5bb1..9b1fb26 100644
--- a/lib/validates_timeliness/helper_methods.rb
+++ b/lib/validates_timeliness/helper_methods.rb
@@ -5,7 +5,7 @@ module ValidatesTimeliness
     included do
       include ValidationMethods
       extend ValidationMethods
-      class_inheritable_hash :timeliness_validated_attributes
+      class_attribute :timeliness_validated_attributes
       self.timeliness_validated_attributes = {}
     end
 
@@ -30,7 +30,7 @@ module ValidatesTimeliness
           validated[attr_name] = type
           validated
         }
-        self.timeliness_validated_attributes = attributes
+        self.timeliness_validated_attributes.update(attributes)
         validates_with Validator, options
       end