diff --git a/internal/querynode/type_def.go b/internal/querynode/type_def.go
index 173a740fed..3be63625db 100644
--- a/internal/querynode/type_def.go
+++ b/internal/querynode/type_def.go
@@ -38,6 +38,7 @@ type (
 	ConsumeSubName = string
 )
 
+// TimeRange is a range of time periods
 type TimeRange struct {
 	timestampMin Timestamp
 	timestampMax Timestamp