diff --git a/addons/crm/models/crm_lead.py b/addons/crm/models/crm_lead.py
index ba6ff745235..fb44fc24f85 100644
--- a/addons/crm/models/crm_lead.py
+++ b/addons/crm/models/crm_lead.py
@@ -1335,7 +1335,7 @@ class Lead(models.Model):
             raise UserError(_('Please select more than one element (lead or opportunity) from the list view.'))
 
         if max_length and len(self.ids) > max_length and not self.env.is_superuser():
-            raise UserError(_("To prevent data loss, Leads and Opportunities can only be merged by groups of %(max_length)s."))
+            raise UserError(_("To prevent data loss, Leads and Opportunities can only be merged by groups of %(max_length)s.", max_length=max_length))
 
         opportunities = self._sort_by_confidence_level(reverse=True)
 
diff --git a/addons/crm/wizard/crm_merge_opportunities_views.xml b/addons/crm/wizard/crm_merge_opportunities_views.xml
index 4d34d43a1e2..75d7717f7a5 100644
--- a/addons/crm/wizard/crm_merge_opportunities_views.xml
+++ b/addons/crm/wizard/crm_merge_opportunities_views.xml
@@ -17,8 +17,8 @@
                                 <field name="name"/>
                                 <field name="type"/>
                                 <field name="contact_name"/>
-                                <field name="email_from"/>
-                                <field name="phone" class="o_force_ltr"/>
+                                <field name="email_from" optional="hide"/>
+                                <field name="phone" class="o_force_ltr" optional="hide"/>
                                 <field name="stage_id"/>
                                 <field name="user_id"/>
                                 <field name="team_id"/>