diff --git a/addons/crm_helpdesk/crm_helpdesk_view.xml b/addons/crm_helpdesk/crm_helpdesk_view.xml
index fe2f727c248..19fe23d3f5c 100644
--- a/addons/crm_helpdesk/crm_helpdesk_view.xml
+++ b/addons/crm_helpdesk/crm_helpdesk_view.xml
@@ -96,7 +96,7 @@
                             <group colspan="4">
                                 <field colspan="4" name="email_cc" string="Global CC" widget="char"/>
                             </group>
-                            <field name="message_ids" colspan="4" nolabel="1" mode="tree,form">
+                            <field name="message_ids" colspan="4" nolabel="1" mode="tree,form" readonly="1">
                                 <tree string="History">
                                     <field name="display_text" string="History Information"/>
                                     <field name="history" invisible="1"/>