diff --git a/internal/indexcoord/task.go b/internal/indexcoord/task.go
index 6bf6bbdee6..adee63c6f2 100644
--- a/internal/indexcoord/task.go
+++ b/internal/indexcoord/task.go
@@ -41,7 +41,7 @@ type task interface {
 	Execute(ctx context.Context) error
 	PostExecute(ctx context.Context) error
 	WaitToFinish() error
-	Notify(err error)
+	Notify(err error) // notify if task is terminated
 	OnEnqueue() error
 }