diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c b/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
index bf7ef1b..a157107 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
@@ -322,7 +322,7 @@
 		}
 
 		tx_slot = ath9k_htc_tx_get_slot(priv);
-		if (tx_slot != 0) {
+		if (tx_slot < 0) {
 			ath_dbg(common, ATH_DBG_XMIT, "No free CAB slot\n");
 			dev_kfree_skb_any(skb);
 			goto next;