diff --git a/Storage/Storage/LCObject.cs b/Storage/Storage/LCObject.cs
index 67bc2dd..0c302b2 100644
--- a/Storage/Storage/LCObject.cs
+++ b/Storage/Storage/LCObject.cs
@@ -126,7 +126,7 @@ namespace LeanCloud.Storage {
                     throw new ArgumentException("key should not start with '_'");
                 }
                 if (key == "objectId" || key == "createdAt" || key == "updatedAt" ||
-                    key == "className" || key == "ACL") {
+                    key == "className") {
                     throw new ArgumentException($"{key} is reserved by LeanCloud");
                 }
                 LCSetOperation setOp = new LCSetOperation(value);