diff --git a/agg-rx.c b/agg-rx.c
index 8df0d41f..73c8b280 100644
--- a/agg-rx.c
+++ b/agg-rx.c
@@ -246,8 +246,7 @@ int mt76_rx_aggr_start(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno,
 
 	mt76_rx_aggr_stop(dev, wcid, tidno);
 
-	tid = kzalloc(sizeof(*tid) + size * sizeof(tid->reorder_buf[0]),
-		      GFP_KERNEL);
+	tid = kzalloc(struct_size(tid, reorder_buf, size), GFP_KERNEL);
 	if (!tid)
 		return -ENOMEM;