diff --git a/lib/action_controller/serialization.rb b/lib/action_controller/serialization.rb
index 7861c117..30c5c1b3 100644
--- a/lib/action_controller/serialization.rb
+++ b/lib/action_controller/serialization.rb
@@ -10,6 +10,12 @@ module ActionController
     # Deprecated
     ADAPTER_OPTION_KEYS = ActiveModel::SerializableResource::ADAPTER_OPTION_KEYS
 
+    module ClassMethods
+      def serialization_scope(scope)
+        self._serialization_scope = scope
+      end
+    end
+
     included do
       class_attribute :_serialization_scope
       self._serialization_scope = :current_user
@@ -59,11 +65,5 @@ module ActionController
         super(serializable_resource, options)
       end
     end
-
-    module ClassMethods
-      def serialization_scope(scope)
-        self._serialization_scope = scope
-      end
-    end
   end
 end