diff --git a/addons/mail/static/src/js/mail_followers.js b/addons/mail/static/src/js/mail_followers.js
index 9f88116acc7..d08a0e7876b 100644
--- a/addons/mail/static/src/js/mail_followers.js
+++ b/addons/mail/static/src/js/mail_followers.js
@@ -217,7 +217,7 @@ openerp_mail_followers = function(session, mail) {
             var self = this;
             var subtype_list_ul = this.$('.oe_subtype_list');
             subtype_list_ul.empty();
-            var records = data[this.view.datarecord.id || this.view.dataset.ids[0]].message_subtype_data;
+            var records = data[this.view.datarecord.id || 'null'].message_subtype_data;
             var nb_subtype = 0;
             _(records).each(function (record) {nb_subtype++;});
             if (nb_subtype > 1) {