diff --git a/addons/account/models/account_invoice.py b/addons/account/models/account_invoice.py
index 3dfe2416616..e5afb8f9bdc 100644
--- a/addons/account/models/account_invoice.py
+++ b/addons/account/models/account_invoice.py
@@ -573,6 +573,8 @@ class AccountInvoice(models.Model):
         to_open_invoices = self.filtered(lambda inv: inv.state != 'open')
         if to_open_invoices.filtered(lambda inv: inv.state != 'draft'):
             raise UserError(_("Invoice must be in draft state in order to validate it."))
+        if to_open_invoices.filtered(lambda inv: inv.amount_total < 0):
+            raise UserError(_("You cannot validate an invoice with a negative total amount. You should create a refund instead."))
         to_open_invoices.action_date_assign()
         to_open_invoices.action_move_create()
         return to_open_invoices.invoice_validate()