diff --git a/merge_duplicate_contacts/models/res_partner.py b/merge_duplicate_contacts/models/res_partner.py
index f77d4d0dcb84..4bc6587c5a15 100644
--- a/merge_duplicate_contacts/models/res_partner.py
+++ b/merge_duplicate_contacts/models/res_partner.py
@@ -45,7 +45,6 @@ def open_wizard_action(self):
             raise UserError(
                 _("At least two records are needed to perform this action.")
             )
-            return
         context = {}
         data = self.prepare_wizard_data()
         wizard = self.env["base.partner.merge.automatic.wizard"].create(data)
diff --git a/merge_duplicate_contacts/wizard/merge_contact.py b/merge_duplicate_contacts/wizard/merge_contact.py
index 4228ef4937d1..0f544a1b1c0d 100644
--- a/merge_duplicate_contacts/wizard/merge_contact.py
+++ b/merge_duplicate_contacts/wizard/merge_contact.py
@@ -192,7 +192,7 @@ def _generate_query(self, fields, maximum_group=100):
         if self.without_sales_orders:
             where_queries.append(
                 """
-                    id IN
+                    id NOT IN
                     (
                         SELECT partner_id FROM sale_order
                         UNION