diff --git a/src/nameserver/namespace.cc b/src/nameserver/namespace.cc
index 915ba95c..d5ea3520 100644
--- a/src/nameserver/namespace.cc
+++ b/src/nameserver/namespace.cc
@@ -728,14 +728,13 @@ bool NameSpace::RebuildBlockMap(std::function<void (const FileInfo&)> callback)
         }
         LOG(INFO, "Check orphan done, %lu entries", orphan_entrys.size());
         if (FLAGS_remove_orphan_entry) {
-            for (std::vector<std::pair<std::string, std::string> >::iterator it =
-                    orphan_entrys.begin(); it != orphan_entrys.end(); ++it) {
+            for (auto& it : orphan_entrys) {
                 int64_t entry_id;
                 std::string name;
-                DecodingStoreKey((*it).first, &entry_id, &name);
+                DecodingStoreKey(it.first, &entry_id, &name);
                 FileInfo file_info;
-                file_info.ParseFromArray((*it).second.data(), (*it).second.size());
-                db_->Delete(leveldb::WriteOptions(), (*it).first);
+                file_info.ParseFromArray(it.second.data(), it.second.size());
+                db_->Delete(leveldb::WriteOptions(), it.first);
                 LOG(INFO, "Remove orphan entry E%ld", entry_id);
             }
         }