diff --git a/verdigado_attendance/data/base_ical.xml b/verdigado_attendance/data/base_ical.xml
index 3f8639e..30b1076 100644
--- a/verdigado_attendance/data/base_ical.xml
+++ b/verdigado_attendance/data/base_ical.xml
@@ -9,7 +9,7 @@
         <field name="expression_dtstart">(record.request_unit_half or record.request_unit_hours) and record.date_from or record.date_from.date()</field>
         <field name="expression_dtend">(record.request_unit_half or record.request_unit_hours) and record.date_to or (record.date_to.date() + timedelta(days=1))</field>
         <!-- prettier-ignore-end -->
-        <field name="expression_summary">record.name</field>
+        <field name="expression_summary">record.name or ''</field>
         <field name="auto" eval="True" />
         <field name="show_on_holiday_calendar" eval="True" />
     </record>
@@ -25,7 +25,7 @@
         <field name="expression_dtstart">(record.request_unit_half or record.request_unit_hours) and record.date_from or record.date_from.date()</field>
         <field name="expression_dtend">(record.request_unit_half or record.request_unit_hours) and record.date_to or (record.date_to.date() + timedelta(days=1))</field>
         <!-- prettier-ignore-end -->
-        <field name="expression_summary">record.name</field>
+        <field name="expression_summary">record.name or ''</field>
         <field name="auto" eval="True" />
         <field name="show_on_holiday_calendar" eval="True" />
     </record>