diff --git a/mac80211.c b/mac80211.c
index a46884d6..bc3a7514 100644
--- a/mac80211.c
+++ b/mac80211.c
@@ -267,7 +267,8 @@ static void mt76_init_stream_cap(struct mt76_phy *phy,
 	}
 	vht_cap->vht_mcs.rx_mcs_map = cpu_to_le16(mcs_map);
 	vht_cap->vht_mcs.tx_mcs_map = cpu_to_le16(mcs_map);
-	vht_cap->vht_mcs.tx_highest |=
+	if (ieee80211_hw_check(phy->hw, SUPPORTS_VHT_EXT_NSS_BW))
+		vht_cap->vht_mcs.tx_highest |=
 				cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE);
 }