diff --git a/sys/net80211/ieee80211_var.h b/sys/net80211/ieee80211_var.h
index 53139a3852b8..a1c4f17208ab 100644
--- a/sys/net80211/ieee80211_var.h
+++ b/sys/net80211/ieee80211_var.h
@@ -244,10 +244,11 @@ struct ieee80211com {
        uint8_t                 ic_txstream;    /* # TX streams */
 
        /* VHT information */
-       uint32_t                ic_vht_flags;   /* VHT state flags */
+       uint32_t                ic_vht_flags;   /* VHT state flags (IEEE80211_FVHT) */
        struct ieee80211_vht_cap ic_vht_cap;    /* VHT capabilities + MCS info */
        uint32_t                ic_vhtextcaps;  /* VHT extended capabilities (TODO) */
-       uint32_t                ic_vht_spare[3];
+       uint32_t                ic_vht_conf;    /* VHT config (IEEE80211_FVHT) */
+       uint32_t                ic_vht_spare[2];
 
        /* optional state for Atheros SuperG protocol extensions */
        struct ieee80211_superg *ic_superg;
diff --git a/sys/net80211/ieee80211_vht.c b/sys/net80211/ieee80211_vht.c
index 0839f426e09c..9c54939db32f 100644
--- a/sys/net80211/ieee80211_vht.c
+++ b/sys/net80211/ieee80211_vht.c
@@ -143,11 +143,25 @@ ieee80211_vht_vattach(struct ieee80211vap *vap)
        vap->iv_vht_cap.vht_cap_info = ic->ic_vht_cap.vht_cap_info;
        vap->iv_vhtextcaps = ic->ic_vhtextcaps;
 
-       /* XXX assume VHT80 support; should really check vhtcaps */
-       vap->iv_vht_flags =
-           IEEE80211_FVHT_VHT
-           | IEEE80211_FVHT_USEVHT40
-           | IEEE80211_FVHT_USEVHT80;
+       vap->iv_vht_flags = IEEE80211_FVHT_VHT;
+
+       /*
+        * This isn't in vht_cap_info, it's actually in the channel config.
+        * So instead check the config.
+        */
+       if (ic->ic_vht_conf & IEEE80211_FVHT_USEVHT40)
+               vap->iv_vht_flags |= IEEE80211_FVHT_USEVHT40;
+       if (ic->ic_vht_conf & IEEE80211_FVHT_USEVHT80)
+               vap->iv_vht_flags |= IEEE80211_FVHT_USEVHT80;
+
+       /*
+        * These are in vht_cap_info, so just use them.
+        *
+        * It may be better to only enable VHT80 if 40 is enabled,
+        * and 160 / 80+80 if 40 is enabled.  It's also likely better
+        * to put the FVHT into the config space and do a sanity check
+        * here.
+        */
        if (IEEE80211_VHTCAP_SUPP_CHAN_WIDTH_IS_160MHZ(vap->iv_vht_cap.vht_cap_info))
                vap->iv_vht_flags |= IEEE80211_FVHT_USEVHT160;
        if (IEEE80211_VHTCAP_SUPP_CHAN_WIDTH_IS_160_80P80MHZ(vap->iv_vht_cap.vht_cap_info))