diff --git a/lib/logstorage/pipe_pack_json.go b/lib/logstorage/pipe_pack_json.go
index 1f3e6191b..ef647f6ec 100644
--- a/lib/logstorage/pipe_pack_json.go
+++ b/lib/logstorage/pipe_pack_json.go
@@ -104,6 +104,7 @@ func (ppp *pipePackJSONProcessor) writeBlock(workerID uint, br *blockResult) {
 		v := bytesutil.ToUnsafeString(buf[bufLen:])
 		shard.rc.addValue(v)
 	}
+	shard.fields = fields
 
 	br.addResultColumn(&shard.rc)
 	ppp.ppNext.writeBlock(workerID, br)
diff --git a/lib/logstorage/pipe_unroll.go b/lib/logstorage/pipe_unroll.go
index 0de54fd47..e1e4e3be9 100644
--- a/lib/logstorage/pipe_unroll.go
+++ b/lib/logstorage/pipe_unroll.go
@@ -201,6 +201,7 @@ func (shard *pipeUnrollProcessorShard) writeUnrolledFields(br *blockResult, fiel
 		}
 		shard.wctx.writeRow(rowIdx, fields)
 	}
+	shard.fields = fields
 }
 
 func (pup *pipeUnrollProcessor) flush() error {