diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 6cc28ca5d4a6..fdcb4e9b4560 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -281,7 +281,8 @@ minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 				break;
 
 		/* short preamble */
-		if (!(mi->supported[group] & BIT(idx)))
+		if ((mi->supported[group] & BIT(idx + 4)) &&
+		    (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
 			idx += 4;
 	}
 	return &mi->groups[group].rates[idx];
@@ -1080,18 +1081,23 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
 		return;
 
 	sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
+	sample_idx %= MCS_GROUP_RATES;
+
+	if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
+	    (sample_idx >= 4) != txrc->short_preamble)
+		return;
+
 	info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
 	rate->count = 1;
 
-	if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
+	if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
 		int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
 		rate->idx = mp->cck_rates[idx];
 	} else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
 		ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
 				       sample_group->streams);
 	} else {
-		rate->idx = sample_idx % MCS_GROUP_RATES +
-			    (sample_group->streams - 1) * 8;
+		rate->idx = sample_idx + (sample_group->streams - 1) * 8;
 	}
 
 	rate->flags = sample_group->flags;