diff --git a/include/rocksdb/write_batch.h b/include/rocksdb/write_batch.h
index e7ce16005..2cfb731f6 100644
--- a/include/rocksdb/write_batch.h
+++ b/include/rocksdb/write_batch.h
@@ -88,7 +88,7 @@ class WriteBatch {
   Status Iterate(Handler* handler) const;
 
   // Retrieve the serialized version of this batch.
-  std::string Data() const { return rep_; }
+  const std::string& Data() const { return rep_; }
 
   // Retrieve data size of the batch.
   size_t GetDataSize() const { return rep_.size(); }