diff --git a/addons/crm/models/crm_lead.py b/addons/crm/models/crm_lead.py
index 06655894e4d..38e03294e52 100644
--- a/addons/crm/models/crm_lead.py
+++ b/addons/crm/models/crm_lead.py
@@ -236,6 +236,8 @@ class Lead(models.Model):
     @api.model
     def _onchange_user_values(self, user_id):
         """ returns new values when user_id has changed """
+        if not user_id:
+            return {}
         if user_id and self._context.get('team_id'):
             team = self.env['crm.team'].browse(self._context['team_id'])
             if user_id in team.member_ids.ids: