1 files changed, 2 insertions, 3 deletions
diff --git a/activemodel/lib/active_model/serializers/json.rb b/activemodel/lib/active_model/serializers/json.rb
index e668b4a009..b4baf3a946 100644
--- a/activemodel/lib/active_model/serializers/json.rb
+++ b/activemodel/lib/active_model/serializers/json.rb
@@ -10,9 +10,8 @@ module ActiveModel
 
       included do
         extend ActiveModel::Naming
-        extend ActiveModel::Configuration
 
-        config_attribute :include_root_in_json
+        class_attribute :include_root_in_json
         self.include_root_in_json = false
       end
 
@@ -106,4 +105,4 @@ module ActiveModel
       end
     end
   end
-end
-\ No newline at end of file
+end