lib/active_model/serializers/json.rb in activemodel-4.1.14 vs lib/active_model/serializers/json.rb in activemodel-4.1.14.1

@@ -8,10 +8,10 @@
       include ActiveModel::Serialization
 
       included do
         extend ActiveModel::Naming
 
-        class_attribute :include_root_in_json
+        class_attribute :include_root_in_json, instance_writer: false
         self.include_root_in_json = false
       end
 
       # Returns a hash representing the model. Some configuration can be
       # passed through +options+.