diff --git a/sys/dev/rtwn/if_rtwn.c b/sys/dev/rtwn/if_rtwn.c
--- a/sys/dev/rtwn/if_rtwn.c
+++ b/sys/dev/rtwn/if_rtwn.c
@@ -436,6 +436,29 @@
 	ieee80211_resume_all(ic);
 }
 
+void
+rtwn_attach_vht_cap_info_mcs(struct rtwn_softc *sc)
+{
+	struct ieee80211com *ic = &sc->sc_ic;
+	uint32_t rx_mcs = 0, 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;
+}
+
 static void
 rtwn_vap_decrement_counters(struct rtwn_softc *sc,
     enum ieee80211_opmode opmode, int id)
diff --git a/sys/dev/rtwn/if_rtwnvar.h b/sys/dev/rtwn/if_rtwnvar.h
--- a/sys/dev/rtwn/if_rtwnvar.h
+++ b/sys/dev/rtwn/if_rtwnvar.h
@@ -446,6 +446,8 @@
 void	rtwn_resume(struct rtwn_softc *);
 void	rtwn_suspend(struct rtwn_softc *);
 
+void	rtwn_attach_vht_cap_info_mcs(struct rtwn_softc *sc);
+
 /* Interface-specific. */
 #define rtwn_write_1(_sc, _addr, _val) \
 	(((_sc)->sc_write_1)((_sc), (_addr), (_val)))
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
@@ -174,11 +174,24 @@
 	}
 
 	ic->ic_htcaps |=
-	    IEEE80211_HTCAP_CHWIDTH40 /* 40 MHz channel width */
-	    | IEEE80211_HTCAP_SHORTGI40 /* short GI in 40MHz */
+	    IEEE80211_HTCAP_CHWIDTH40 | /* 40 MHz channel width */
+	    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);
+
+	rtwn_attach_vht_cap_info_mcs(sc);
 }
 
 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
@@ -159,11 +159,22 @@
 		ic->ic_caps |= IEEE80211_C_DFS;
 
 	ic->ic_htcaps |=
-	    IEEE80211_HTCAP_CHWIDTH40 /* 40 MHz channel width */
-	    | IEEE80211_HTCAP_SHORTGI40 /* short GI in 40MHz */
+	    IEEE80211_HTCAP_CHWIDTH40 | /* 40 MHz channel width */
+	    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);
+
+	rtwn_attach_vht_cap_info_mcs(sc);
 }
 
 void