diff --git a/l10n_it_declaration_of_intent/wizard/select_declarations.py b/l10n_it_declaration_of_intent/wizard/select_declarations.py
index ab1178bd08fc..d6a6dd314c55 100644
--- a/l10n_it_declaration_of_intent/wizard/select_declarations.py
+++ b/l10n_it_declaration_of_intent/wizard/select_declarations.py
@@ -46,6 +46,8 @@ def confirm(self):
         if not invoice_id:
             return res
         invoice = self.env["account.move"].browse(invoice_id)
+        declaration_of_intent_ids = [(5, 0)]
         for declaration in self.declaration_ids:
-            invoice.declaration_of_intent_ids = [(4, declaration.id)]
+            declaration_of_intent_ids.append((4, declaration.id))
+        invoice.declaration_of_intent_ids = declaration_of_intent_ids
         return True