diff --git a/addons/calendar/views/calendar_views.xml b/addons/calendar/views/calendar_views.xml
index 9e2d8765a48..5bbede975da 100644
--- a/addons/calendar/views/calendar_views.xml
+++ b/addons/calendar/views/calendar_views.xml
@@ -108,7 +108,7 @@
                 </div>
                 <sheet>
                     <div class="oe_button_box" name="button_box">
-                        <button icon="fa-bars" type="object" name="action_open_calendar_event" invisible="not res_id">
+                        <button icon="fa-bars" type="object" name="action_open_calendar_event" invisible="not (res_id and res_model_name)">
                             <field name="res_model_name"/>
                         </button>
                     </div>