diff --git a/drivers/net/wireless/ath/ath5k/attach.c b/drivers/net/wireless/ath/ath5k/attach.c
index dd4099a2ff15..f80d3d52c536 100644
--- a/drivers/net/wireless/ath/ath5k/attach.c
+++ b/drivers/net/wireless/ath/ath5k/attach.c
@@ -123,6 +123,7 @@ int ath5k_hw_attach(struct ath5k_softc *sc)
 	ah->ah_limit_tx_retries = AR5K_INIT_TX_RETRY;
 	ah->ah_software_retry = false;
 	ah->ah_ant_mode = AR5K_ANTMODE_DEFAULT;
+	ah->ah_noise_floor = -95;	/* until first NF calibration is run */
 
 	/*
 	 * Find the mac version