diff --git a/mac80211.c b/mac80211.c
index 62807dc3..b0869ff8 100644
--- a/mac80211.c
+++ b/mac80211.c
@@ -1494,7 +1494,6 @@ EXPORT_SYMBOL_GPL(mt76_init_queue);
 u16 mt76_calculate_default_rate(struct mt76_phy *phy, int rateidx)
 {
 	int offset = 0;
-	struct ieee80211_rate *rate;
 
 	if (phy->chandef.chan->band != NL80211_BAND_2GHZ)
 		offset = 4;
@@ -1503,9 +1502,11 @@ u16 mt76_calculate_default_rate(struct mt76_phy *phy, int rateidx)
 	if (rateidx < 0)
 		rateidx = 0;
 
-	rate = &mt76_rates[offset + rateidx];
+	rateidx += offset;
+	if (rateidx >= ARRAY_SIZE(mt76_rates))
+		rateidx = offset;
 
-	return rate->hw_value;
+	return mt76_rates[rateidx].hw_value;
 }
 EXPORT_SYMBOL_GPL(mt76_calculate_default_rate);