--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1497,6 +1497,7 @@ EXPORT_SYMBOL(ath9k_hw_keyreset);
 bool ath9k_hw_keysetmac(struct ath_hw *ah, u16 entry, const u8 *mac)
 {
 	u32 macHi, macLo;
+	u32 unicast_flag = AR_KEYTABLE_VALID;
 
 	if (entry >= ah->caps.keycache_size) {
 		ath_print(ath9k_hw_common(ah), ATH_DBG_FATAL,
@@ -1505,6 +1506,16 @@ bool ath9k_hw_keysetmac(struct ath_hw *a
 	}
 
 	if (mac != NULL) {
+		/*
+		 * AR_KEYTABLE_VALID indicates that the address is a unicast
+		 * address, which must match the transmitter address for
+		 * decrypting frames.
+		 * Not setting this bit allows the hardware to use the key
+		 * for multicast frame decryption.
+		 */
+		if (mac[0] & 0x01)
+			unicast_flag = 0;
+
 		macHi = (mac[5] << 8) | mac[4];
 		macLo = (mac[3] << 24) |
 			(mac[2] << 16) |
@@ -1517,7 +1528,7 @@ bool ath9k_hw_keysetmac(struct ath_hw *a
 		macLo = macHi = 0;
 	}
 	REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), macLo);
-	REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), macHi | AR_KEYTABLE_VALID);
+	REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), macHi | unicast_flag);
 
 	return true;
 }