diff --git a/pyicloud/base.py b/pyicloud/base.py
index c7becd5..e700c73 100644
--- a/pyicloud/base.py
+++ b/pyicloud/base.py
@@ -63,7 +63,7 @@ class PyiCloudService(object):
         if 'dsInfo' in resp:
             dsid = resp['dsInfo']['dsid']
             self.params.update({'dsid': dsid})
-        instance = resp['instance']
+        instance = resp.get('instance', uuid.uuid4().hex)
         sha = hashlib.sha1(self.user.get('apple_id') + instance)
         self.params.update({'id': sha.hexdigest().upper()})