diff --git a/lib/ontologies_linked_data/models/ontology_submission.rb b/lib/ontologies_linked_data/models/ontology_submission.rb
index ea054284..fef44a8b 100644
--- a/lib/ontologies_linked_data/models/ontology_submission.rb
+++ b/lib/ontologies_linked_data/models/ontology_submission.rb
@@ -35,7 +35,7 @@ class OntologySubmission < LinkedData::Models::Base
       attribute :homepage
       attribute :publication
       attribute :uri, namespace: :omv
-      attribute :naturalLanguage, namespace: :omv
+      attribute :naturalLanguage, namespace: :omv, enforce: [:list]
       attribute :documentation, namespace: :omv
       attribute :version, namespace: :omv
       attribute :creationDate, namespace: :omv, enforce: [:date_time], default: lambda { |record| DateTime.now }