diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index 11bc55e3d69759088e34433ce19c74ee9ef9e5b1..70b802529123ba0e81b82ddcef46605e1b8189b5 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -48,7 +48,10 @@ int ath_beaconq_config(struct ath_softc *sc)
 		txq = sc->tx.txq_map[WME_AC_BE];
 		ath9k_hw_get_txq_props(ah, txq->axq_qnum, &qi_be);
 		qi.tqi_aifs = qi_be.tqi_aifs;
-		qi.tqi_cwmin = 4*qi_be.tqi_cwmin;
+		if (ah->slottime == ATH9K_SLOT_TIME_20)
+			qi.tqi_cwmin = 2*qi_be.tqi_cwmin;
+		else
+			qi.tqi_cwmin = 4*qi_be.tqi_cwmin;
 		qi.tqi_cwmax = qi_be.tqi_cwmax;
 	}