diff --git a/mt76x2_mac.c b/mt76x2_mac.c
index 4bcdd95d..2ceccadd 100644
--- a/mt76x2_mac.c
+++ b/mt76x2_mac.c
@@ -568,26 +568,6 @@ int mt76x2_mac_shared_key_setup(struct mt76x2_dev *dev, u8 vif_idx, u8 key_idx,
 	return 0;
 }
 
-int mt76x2_mac_skb_tx_overhead(struct mt76x2_dev *dev, struct sk_buff *skb)
-{
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	struct ieee80211_key_conf *key = info->control.hw_key;
-	int overhead;
-
-	if (!key)
-		return 0;
-
-	overhead = key->icv_len;
-	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV))
-		overhead += key->iv_len;
-
-	if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
-	    key->cipher == WLAN_CIPHER_SUITE_TKIP)
-		overhead += 8;
-
-	return overhead;
-}
-
 static int
 mt76_write_beacon(struct mt76x2_dev *dev, int offset, struct sk_buff *skb)
 {
diff --git a/mt76x2_mac.h b/mt76x2_mac.h
index e131f524..c7e067c7 100644
--- a/mt76x2_mac.h
+++ b/mt76x2_mac.h
@@ -171,8 +171,6 @@ void mt76x2_mac_wcid_set_rate(struct mt76x2_dev *dev, struct mt76_wcid *wcid,
 int mt76x2_mac_shared_key_setup(struct mt76x2_dev *dev, u8 vif_idx, u8 key_idx,
 			      struct ieee80211_key_conf *key);
 
-int mt76x2_mac_skb_tx_overhead(struct mt76x2_dev *dev, struct sk_buff *skb);
-
 int mt76x2_mac_set_beacon(struct mt76x2_dev *dev, u8 vif_idx, struct sk_buff *skb);
 void mt76x2_mac_set_beacon_enable(struct mt76x2_dev *dev, u8 vif_idx, bool val);