diff --git a/table/cuckoo_table_reader.cc b/table/cuckoo_table_reader.cc
index f8da4e288..f39900add 100644
--- a/table/cuckoo_table_reader.cc
+++ b/table/cuckoo_table_reader.cc
@@ -191,7 +191,7 @@ class CuckooTableIterator : public Iterator {
 
  private:
   struct BucketComparator {
-    BucketComparator(const Slice file_data, const Comparator* ucomp,
+    BucketComparator(const Slice& file_data, const Comparator* ucomp,
                      uint32_t bucket_len, uint32_t user_key_len,
                      const Slice target = Slice())
       : file_data_(file_data),