diff --git a/core/mr/mapreduce.go b/core/mr/mapreduce.go
index edb32808..a56a82fe 100644
--- a/core/mr/mapreduce.go
+++ b/core/mr/mapreduce.go
@@ -363,9 +363,7 @@ func newGuardedWriter[T any](ctx context.Context, channel chan<- T, done <-chan
 func (gw guardedWriter[T]) Write(v T) {
 	select {
 	case <-gw.ctx.Done():
-		return
 	case <-gw.done:
-		return
 	default:
 		gw.channel <- v
 	}