diff --git a/aliyun/log/external_store_config.py b/aliyun/log/external_store_config.py
index 1d3e2b0..b1ebef0 100644
--- a/aliyun/log/external_store_config.py
+++ b/aliyun/log/external_store_config.py
@@ -59,7 +59,7 @@ def to_json(self):
         json_value["storeType"] = self.storeType
         param = {}
         param["vpc-id"] = self.vpcId
-        param["instance-id"] = self.instanceId
+        param["instance-id"] = self.instanceId or ""
         param["host"] = self.host
         param["port"] = self.port
         param["username"] = self.username
diff --git a/aliyun/log/version.py b/aliyun/log/version.py
index 28a6443..63995e9 100644
--- a/aliyun/log/version.py
+++ b/aliyun/log/version.py
@@ -1,4 +1,4 @@
-__version__ = '0.9.45'
+__version__ = '0.9.46'
 
 import sys
 OS_VERSION = str(sys.platform)