diff --git a/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c b/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c
index af7b732183f4..e0ebda1748f5 100644
--- a/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c
+++ b/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c
@@ -73,8 +73,15 @@ ar5416IsCalSupp(struct ath_hal *ah, const struct ieee80211_channel *chan,
 	case ADC_GAIN_CAL:
 	case ADC_DC_CAL:
 		/* Run ADC Gain Cal for either 5ghz any or 2ghz HT40 */
-		if (IEEE80211_IS_CHAN_5GHZ(chan))
-			return AH_TRUE;
+		/*
+		 * Merlin (AR9280) doesn't ever complete ADC calibrations
+		 * in 5ghz non-HT40 mode (ie, HT20, 11a). For now, disable
+		 * it for Merlin only until further information is
+		 * available.
+		 */
+		if (! AR_SREV_MERLIN(ah))
+			if (IEEE80211_IS_CHAN_5GHZ(chan))
+				return AH_TRUE;
 		if (IEEE80211_IS_CHAN_HT40(chan))
 			return AH_TRUE;
 		return AH_FALSE;