diff --git a/os_dep/linux/ioctl_cfg80211.c b/os_dep/linux/ioctl_cfg80211.c
index bbe9832..f5ccbb2 100644
--- a/os_dep/linux/ioctl_cfg80211.c
+++ b/os_dep/linux/ioctl_cfg80211.c
@@ -9288,7 +9288,13 @@ static void rtw_cfg80211_init_ht_capab(_adapter *padapter
 
 	ht_cap->ht_supported = 1;
 
-	ht_cap->cap = IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
+	/* According to the comment in rtw_ap.c:
+	 * "Note: currently we switch to the MIXED op mode if HT non-greenfield
+	 * station is associated. Probably it's a theoretical case, since
+	 * it looks like all known HT STAs support greenfield."
+	 * Therefore Greenfield is added to ht_cap
+	 */
+	ht_cap->cap = IEEE80211_HT_CAP_SUP_WIDTH_20_40 | IEEE80211_HT_CAP_GRN_FLD |
 				IEEE80211_HT_CAP_SGI_40 | IEEE80211_HT_CAP_SGI_20 |
 				IEEE80211_HT_CAP_DSSSCCK40 | IEEE80211_HT_CAP_MAX_AMSDU;
 	rtw_cfg80211_init_ht_capab_ex(padapter, ht_cap, band, rf_type);