diff --git a/addons/mail/data/mail_demo.xml b/addons/mail/data/mail_demo.xml
index 7bda32c002b..bda93fc485d 100644
--- a/addons/mail/data/mail_demo.xml
+++ b/addons/mail/data/mail_demo.xml
@@ -8,6 +8,7 @@
             <field name="body">Your monthly meal vouchers arrived. You can get them at Christine's office.
 This month you also get 250 EUR of eco-vouchers if you have been in the company for more than a year.</field>
             <field name="type">comment</field>
+            <field name="subtype_id" ref="mt_comment"/>
         </record>
 
         <record id="message_blogpost0_comment0" model="mail.message">
@@ -16,6 +17,7 @@ This month you also get 250 EUR of eco-vouchers if you have been in the company
             <field name="body"><![CDATA[Great.]]></field>
             <field name="parent_id" ref="message_blogpost0"/>
             <field name="type">comment</field>
+            <field name="subtype_id" ref="mt_comment"/>
         </record>
 
         <record id="message_blogpost0_comment1" model="mail.message">
@@ -24,22 +26,25 @@ This month you also get 250 EUR of eco-vouchers if you have been in the company
             <field name="body">Thanks, but where is Christine's office, if I may ask? (I'm new here)</field>
             <field name="parent_id" ref="message_blogpost0"/>
             <field name="type">comment</field>
+            <field name="subtype_id" ref="mt_comment"/>
         </record>
 
         <record id="message_blogpost0_comment2" model="mail.message">
+            <field name="model">mail.group</field>
+            <field name="res_id" ref="group_all_employees"/>
+            <field name="body">Building B3, second floor on the right :-)</field>
+            <field name="parent_id" ref="message_blogpost0"/>
+            <field name="type">comment</field>
+            <field name="subtype_id" ref="mt_comment"/>
+        </record>
+
+        <record id="message_blogpost0_comment3" model="mail.message">
             <field name="model">mail.group</field>
             <field name="res_id" ref="group_all_employees"/>
             <field name="body">Great news, I need to buy a new fridge, I think I can pay it with the eco-vouchers!</field>
             <field name="parent_id" ref="message_blogpost0"/>
             <field name="type">comment</field>
-        </record>
-
-        <record id="message_blogpost0_comment1_2" model="mail.message">
-            <field name="model">mail.group</field>
-            <field name="res_id" ref="group_all_employees"/>
-            <field name="body">Building B3, second floor on the right :-)</field>
-            <field name="parent_id" ref="message_blogpost0_comment1"/>
-            <field name="type">comment</field>
+            <field name="subtype_id" ref="mt_comment"/>
         </record>
 
     </data>