diff --git a/addons/calendar/data/mail_data.xml b/addons/calendar/data/mail_data.xml
index a4e2fa46907..bd44813d08f 100644
--- a/addons/calendar/data/mail_data.xml
+++ b/addons/calendar/data/mail_data.xml
@@ -8,6 +8,7 @@
             <field name="email_from">${object.event_id.user_id.email or ''}</field>
             <field name="email_to" >${('' if object.partner_id and object.partner_id.email and object.partner_id.email==object.email else object.email|safe)}</field>
             <field name="partner_to">${object.partner_id and object.partner_id.email and object.partner_id.email==object.email and object.partner_id.id or False }</field>
+            <field name="lang">${object.partner_id.lang}</field>
             <field name="body_html" type="html">
 <div>
     % set colors = {'needsAction': 'grey', 'accepted': 'green', 'tentative': '#FFFF00',  'declined': 'red'}
@@ -91,6 +92,7 @@
             <field name="email_from">${object.event_id.user_id.email or ''}</field>
             <field name="email_to" >${('' if object.partner_id and object.partner_id.email and object.partner_id.email==object.email else object.email|safe)}</field>
             <field name="partner_to">${object.partner_id and object.partner_id.email and object.partner_id.email==object.email and object.partner_id.id or False }</field>
+            <field name="lang">${object.partner_id.lang}</field>
             <field name="body_html" type="html">
 <div>
     % set colors = {'needsAction': 'grey', 'accepted': 'green', 'tentative': '#FFFF00',  'declined': 'red'}
@@ -174,6 +176,7 @@
             <field name="email_from">${object.event_id.user_id.email or ''}</field>
             <field name="email_to" >${('' if object.partner_id and object.partner_id.email and object.partner_id.email==object.email else object.email|safe)}</field>
             <field name="partner_to">${object.partner_id and object.partner_id.email and object.partner_id.email==object.email and object.partner_id.id or False }</field>
+            <field name="lang">${object.partner_id.lang}</field>
             <field name="body_html" type="html">
 <div>
     % set colors = {'needsAction': 'grey', 'accepted': 'green', 'tentative': '#FFFF00',  'declined': 'red'}