diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 501c783..e8d573d 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -218,12 +218,16 @@
 
 	if (sta->fail_avg >= 100)
 		return MAX_METRIC;
+
+	if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
+		return MAX_METRIC;
+
 	err = (sta->fail_avg << ARITH_SHIFT) / 100;
 
 	/* bitrate is in units of 100 Kbps, while we need rate in units of
 	 * 1Mbps. This will be corrected on tx_time computation.
 	 */
-	rate = sband->bitrates[sta->last_txrate_idx].bitrate;
+	rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
 	tx_time = (device_constant + 10 * test_frame_len / rate);
 	estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
 	result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;