diff --git a/app/models/metadata_factory.rb b/app/models/metadata_factory.rb
index 8cac1c86..c33f1f18 100644
--- a/app/models/metadata_factory.rb
+++ b/app/models/metadata_factory.rb
@@ -2,9 +2,14 @@
 
 # Devuelve metadatos de cierto tipo
 class MetadataFactory
-  def self.build(**args)
-    @@factory_cache ||= {}
-    @@factory_cache[args[:type]] ||= ('Metadata' + args[:type].to_s.camelcase).constantize
-    @@factory_cache[args[:type]].new(args)
+  class << self
+    def build(**args)
+      classify(args[:type]).new(**args)
+    end
+
+    def classify(type)
+      @factory_cache ||= {}
+      @factory_cache[type] ||= ('Metadata' + type.to_s.camelcase).constantize
+    end
   end
 end