diff --git a/partner_second_lastname/views/res_partner.xml b/partner_second_lastname/views/res_partner.xml
index 11ddc162c1d..848fce38e4b 100644
--- a/partner_second_lastname/views/res_partner.xml
+++ b/partner_second_lastname/views/res_partner.xml
@@ -16,7 +16,7 @@
             <field name="lastname" position="after">
                 <field
                     name="lastname2"
-                    required="not lastname2 and not lastname and not is_company and type == 'contact'"
+                    required="not firstname and not lastname and not is_company and type == 'contact'"
                 />
             </field>
         </field>
diff --git a/partner_second_lastname/views/res_user.xml b/partner_second_lastname/views/res_user.xml
index 0bee604dc37..2e0c2402c3e 100644
--- a/partner_second_lastname/views/res_user.xml
+++ b/partner_second_lastname/views/res_user.xml
@@ -15,7 +15,7 @@
                 <attribute name="required" add="(not lastname2)" separator=" and " />
             </field>
             <field name="lastname" position="after">
-                <field name="lastname2" required="not lastname2 and not lastname" />
+                <field name="lastname2" required="not firstname and not lastname" />
             </field>
         </field>
     </record>