diff --git a/app/models/module_api_carto.rb b/app/models/module_api_carto.rb
index cdd53db71..e2a878c69 100644
--- a/app/models/module_api_carto.rb
+++ b/app/models/module_api_carto.rb
@@ -12,5 +12,5 @@
 #  procedure_id           :integer
 #
 class ModuleAPICarto < ApplicationRecord
-  belongs_to :procedure
+  belongs_to :procedure, optional: false
 end