diff --git a/epan/dissectors/packet-ieee80211-radio.c b/epan/dissectors/packet-ieee80211-radio.c
index adb6e4ef1a..25a2b33067 100644
--- a/epan/dissectors/packet-ieee80211-radio.c
+++ b/epan/dissectors/packet-ieee80211-radio.c
@@ -633,8 +633,8 @@ dissect_wlan_radio_phdr (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
                * If we can calculate the data rate for this user, do so.
                */
               if (can_calculate_rate && info_ac->mcs[i] <= MAX_MCS_VHT_INDEX &&
-                  info_ac->nss[i] < MAX_VHT_NSS &&
-                  ieee80211_vhtvalid[info_ac->mcs[i]].valid[bandwidth][info_ac->nss[i]]) {
+                  info_ac->nss[i] <= MAX_VHT_NSS &&
+                  ieee80211_vhtvalid[info_ac->mcs[i]].valid[bandwidth][info_ac->nss[i]-1]) {
                 data_rate = ieee80211_vhtrate(info_ac->mcs[i], bandwidth, info_ac->short_gi) * info_ac->nss[i];
                 if (data_rate != 0.0f) {
                   proto_tree_add_float_format_value(user_tree, hf_wlan_radio_data_rate, tvb, 0, 0,