diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
index 11661fa28f219be6ab34422fbe9dbaafef2a9cac..95e263f1d1177f37213ab464470d5f6829f2095f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
@@ -83,6 +83,15 @@ static inline int get_fifo_from_ac(u8 ac)
 	return ac_to_fifo[ac];
 }
 
+static inline int get_ac_from_tid(u16 tid)
+{
+	if (likely(tid < ARRAY_SIZE(tid_to_ac)))
+		return tid_to_ac[tid];
+
+	/* no support for TIDs 8-15 yet */
+	return -EINVAL;
+}
+
 static inline int get_fifo_from_tid(u16 tid)
 {
 	if (likely(tid < ARRAY_SIZE(tid_to_ac)))
@@ -991,7 +1000,7 @@ int iwlagn_tx_agg_start(struct iwl_priv *priv, const u8 *ra, u16 tid, u16 *ssn)
 	tid_data = &priv->stations[sta_id].tid[tid];
 	*ssn = SEQ_TO_SN(tid_data->seq_number);
 	tid_data->agg.txq_id = txq_id;
-	priv->txq[txq_id].swq_id = iwl_virtual_agg_queue_num(tx_fifo, txq_id);
+	priv->txq[txq_id].swq_id = iwl_virtual_agg_queue_num(get_ac_from_tid(tid), txq_id);
 	spin_unlock_irqrestore(&priv->sta_lock, flags);
 
 	ret = priv->cfg->ops->lib->txq_agg_enable(priv, txq_id, tx_fifo,