diff --git a/contract/i18n/es.po b/contract/i18n/es.po
index 0882c907d..ab1766b16 100644
--- a/contract/i18n/es.po
+++ b/contract/i18n/es.po
@@ -2427,6 +2427,13 @@ msgstr ""
 "{{ object.company_id.name }} Contrato (Ref {{ object.name or 'n/a' }}) - "
 "Modificaciones"
 
+#. module: contract
+#: model:ir.model.fields.selection,name:contract.selection__contract_abstract_contract__generation_type__invoice
+#: model:ir.model.fields.selection,name:contract.selection__contract_contract__generation_type__invoice
+#: model:ir.model.fields.selection,name:contract.selection__contract_template__generation_type__invoice
+msgid "Invoice"
+msgstr "Factura"
+
 #~ msgid "Analytic account"
 #~ msgstr "Cuenta analítica"
 
diff --git a/contract/models/abstract_contract.py b/contract/models/abstract_contract.py
index e8c82f000..70210cec1 100644
--- a/contract/models/abstract_contract.py
+++ b/contract/models/abstract_contract.py
@@ -51,15 +51,11 @@ class ContractAbstractContract(models.AbstractModel):
         " of all together for the whole contract.",
     )
     generation_type = fields.Selection(
-        selection=lambda self: self._selection_generation_type(),
+        selection=[("invoice", "Invoice")],
         default=lambda self: self._default_generation_type(),
         help="Choose the document that will be automatically generated by cron.",
     )
 
-    @api.model
-    def _selection_generation_type(self):
-        return [("invoice", "Invoice")]
-
     @api.model
     def _default_generation_type(self):
         return "invoice"