diff --git a/addons/emails/email_message.py b/addons/emails/email_message.py
index f51b19df207..7aef05d9af3 100644
--- a/addons/emails/email_message.py
+++ b/addons/emails/email_message.py
@@ -85,9 +85,6 @@ class email_message_template(osv.osv_memory):
         'description': fields.text('Description', translate=True),
         'smtp_server_id':fields.many2one('email.smtp_server', 'SMTP Server'),
     }
-    _defaults = {
-        'references': lambda * a: None,
-    }
 
     _sql_constraints = []
 email_message_template()
@@ -273,7 +270,7 @@ class email_message(osv.osv):
                 'reply_to': reply_to,
                 'res_id': openobject_id,
                 'message_id': message_id,
-                'references': references,
+                'references': references or '',
                 'sub_type': subtype or '',
                 'headers': x_headers or False,
                 'priority': priority,
diff --git a/addons/emails/wizard/email_compose_message.py b/addons/emails/wizard/email_compose_message.py
index e951e0f97f1..1f4dfb464be 100644
--- a/addons/emails/wizard/email_compose_message.py
+++ b/addons/emails/wizard/email_compose_message.py
@@ -85,7 +85,7 @@ class email_compose_message(osv.osv_memory):
                 result['user_id'] = message_data and message_data.user_id and message_data.user_id.id or False
 
             if 'references' in fields:
-                result['references'] = tools.ustr(message_data and message_data.references)
+                result['references'] = message_data and message_data.references and tools.ustr(message_data.references)
 
             if 'sub_type' in fields:
                 result['sub_type'] = message_data and message_data.sub_type
@@ -159,7 +159,7 @@ class email_compose_message(osv.osv_memory):
             references = False
             message_id = False
             if context.get('mail',False) == 'reply' and  mail.message_id:
-                references = mail.references and str(mail.references) != 'False' and mail.references + "," + mail.message_id or mail.message_id
+                references = mail.references and mail.references + "," + mail.message_id or mail.message_id
             else:
                 message_id = mail.message_id
             email_id = email_message_pool.email_send(cr, uid, mail.email_from, mail.email_to, mail.name, mail.description,