diff --git a/cmdb-api/api/lib/cmdb/history.py b/cmdb-api/api/lib/cmdb/history.py
index 6d1f542..adc6d40 100644
--- a/cmdb-api/api/lib/cmdb/history.py
+++ b/cmdb-api/api/lib/cmdb/history.py
@@ -135,7 +135,7 @@ class AttributeHistoryManger(object):
         from api.lib.cmdb.ci import CIManager
         cis = CIManager().get_cis_by_ids(list(ci_ids),
                                          unique_required=True)
-        cis = {i['_id']: i for i in cis}
+        cis = {i['_id']: i for i in cis if i}
 
         return total, res, cis