diff --git a/sys/dev/rtwn/rtl8812a/usb/r12au_attach.c b/sys/dev/rtwn/rtl8812a/usb/r12au_attach.c
--- a/sys/dev/rtwn/rtl8812a/usb/r12au_attach.c
+++ b/sys/dev/rtwn/rtl8812a/usb/r12au_attach.c
@@ -167,6 +167,8 @@
 {
 	struct r12a_softc *rs = sc->sc_priv;
 	struct ieee80211com *ic = &sc->sc_ic;
+	uint32_t rx_mcs, tx_mcs;
+
 
 	if (rs->chip & R12A_CHIP_C_CUT) {
 		ic->ic_htcaps |= IEEE80211_HTCAP_LDPC |
@@ -178,7 +180,34 @@
 	    | IEEE80211_HTCAP_SHORTGI40 /* short GI in 40MHz */
 	;
 
-	/* TODO: STBC, VHT etc */
+	/* TODO: STBC */
+
+	/* VHT config */
+	ic->ic_flags_ext |= IEEE80211_FEXT_VHT;
+	ic->ic_vht_cap.vht_cap_info =
+	    IEEE80211_VHTCAP_MAX_MPDU_LENGTH_11454
+	    | IEEE80211_VHTCAP_SHORT_GI_80
+	    | IEEE80211_VHTCAP_TXSTBC
+	    | IEEE80211_VHTCAP_RXSTBC_1
+	    | IEEE80211_VHTCAP_HTC_VHT
+	    | _IEEE80211_SHIFTMASK(7,
+	    IEEE80211_VHTCAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK);
+	rx_mcs = tx_mcs = 0;
+	for (int i = 0 ; i < 8; i++) {
+		if (i < sc->ntxchains)
+			tx_mcs |= (IEEE80211_VHT_MCS_SUPPORT_0_9 << (i*2));
+		else
+			tx_mcs |= (IEEE80211_VHT_MCS_NOT_SUPPORTED << (i*2));
+		if (i < sc->nrxchains)
+			rx_mcs |= (IEEE80211_VHT_MCS_SUPPORT_0_9 << (i*2));
+		else
+			rx_mcs |= (IEEE80211_VHT_MCS_NOT_SUPPORTED << (i*2));
+	}
+
+	ic->ic_vht_cap.supp_mcs.rx_mcs_map = rx_mcs;
+	ic->ic_vht_cap.supp_mcs.rx_highest = 0;
+	ic->ic_vht_cap.supp_mcs.tx_mcs_map = tx_mcs;
+	ic->ic_vht_cap.supp_mcs.tx_highest = 0;
 }
 
 void
diff --git a/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c b/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c
--- a/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c
+++ b/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c
@@ -153,6 +153,8 @@
 {
 	struct ieee80211com *ic = &sc->sc_ic;
 	struct r12a_softc *rs = sc->sc_priv;
+	uint32_t rx_mcs, tx_mcs;
+
 
 	ic->ic_htcaps |= IEEE80211_HTC_TXLDPC;
 	if (rs->rs_radar != 0)
@@ -163,7 +165,31 @@
 	    | IEEE80211_HTCAP_SHORTGI40 /* short GI in 40MHz */
 	    ;
 
-	/* TODO: VHT */
+	/* VHT config */
+	ic->ic_flags_ext |= IEEE80211_FEXT_VHT;
+	ic->ic_vht_cap.vht_cap_info =
+	    IEEE80211_VHTCAP_MAX_MPDU_LENGTH_11454
+	    | IEEE80211_VHTCAP_SHORT_GI_80
+	    | IEEE80211_VHTCAP_TXSTBC
+	    | IEEE80211_VHTCAP_RXSTBC_1
+	    | IEEE80211_VHTCAP_HTC_VHT
+	    | _IEEE80211_SHIFTMASK(7,
+	        IEEE80211_VHTCAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK);
+	rx_mcs = tx_mcs = 0;
+	for (int i = 0 ; i < 8; i++) {
+		if (i < sc->ntxchains)
+			tx_mcs |= (IEEE80211_VHT_MCS_SUPPORT_0_9 << (i*2));
+		else
+			tx_mcs |= (IEEE80211_VHT_MCS_NOT_SUPPORTED << (i*2));
+		if (i < sc->nrxchains)
+			rx_mcs |= (IEEE80211_VHT_MCS_SUPPORT_0_9 << (i*2));
+		else
+			rx_mcs |= (IEEE80211_VHT_MCS_NOT_SUPPORTED << (i*2));
+	}
+	ic->ic_vht_cap.supp_mcs.rx_mcs_map = rx_mcs;
+	ic->ic_vht_cap.supp_mcs.rx_highest = 0;
+	ic->ic_vht_cap.supp_mcs.tx_mcs_map = tx_mcs;
+	ic->ic_vht_cap.supp_mcs.tx_highest = 0;
 }
 
 void