diff --git a/be/src/formats/parquet/column_converter.cpp b/be/src/formats/parquet/column_converter.cpp
index 89e2b1eb41b..35be7fb847b 100644
--- a/be/src/formats/parquet/column_converter.cpp
+++ b/be/src/formats/parquet/column_converter.cpp
@@ -147,7 +147,7 @@ public:
         auto& src_null_data = src_nullable_column->null_column()->get_data();
         auto& dst_null_data = dst_nullable_column->null_column()->get_data();
 
-        size_t size = src_column->size();
+        size_t size = dst_null_data.size();
         memcpy(dst_null_data.data(), src_null_data.data(), size);
         convert_int_to_int<SourceType, DestType>(src_data.data(), dst_data.data(), size);
         dst_nullable_column->set_has_null(src_nullable_column->has_null());