diff --git a/be/src/column/nullable_column.cpp b/be/src/column/nullable_column.cpp
index c4564ef5db560..97b57f50fd7f8 100644
--- a/be/src/column/nullable_column.cpp
+++ b/be/src/column/nullable_column.cpp
@@ -312,7 +312,7 @@ void NullableColumn::fnv_hash(uint32_t* hash, uint32_t from, uint32_t to) const
         return;
     }
 
-    auto null_data = _null_column->get_data();
+    const auto& null_data = _null_column->get_data();
     uint32_t value = 0x9e3779b9;
     while (from < to) {
         uint32_t new_from = from + 1;
@@ -337,7 +337,7 @@ void NullableColumn::crc32_hash(uint32_t* hash, uint32_t from, uint32_t to) cons
         return;
     }
 
-    auto null_data = _null_column->get_data();
+    const auto& null_data = _null_column->get_data();
     // NULL is treat as 0 when crc32 hash for data loading
     static const int INT_VALUE = 0;
     while (from < to) {