diff --git a/internal/core/src/index/JsonKeyStatsInvertedIndex.cpp b/internal/core/src/index/JsonKeyStatsInvertedIndex.cpp
index 29a97c0d3f..0adcb82098 100644
--- a/internal/core/src/index/JsonKeyStatsInvertedIndex.cpp
+++ b/internal/core/src/index/JsonKeyStatsInvertedIndex.cpp
@@ -444,6 +444,7 @@ JsonKeyStatsInvertedIndex::BuildWithFieldData(
             auto n = data->get_num_rows();
             for (int i = 0; i < n; i++) {
                 if (!data->is_valid(i)) {
+                    offset++;
                     continue;
                 }
                 AddJson(static_cast<const milvus::Json*>(data->RawValue(i))