diff --git a/mt7921/main.c b/mt7921/main.c
index d2dce488..4e206f4f 100644
--- a/mt7921/main.c
+++ b/mt7921/main.c
@@ -807,6 +807,9 @@ int mt7921_mac_sta_add(struct mt76_dev *mdev, struct ieee80211_vif *vif,
 	struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv;
 	int ret, idx;
 
+	if (sta->aid > MT7921_MAX_AID)
+		return -ENOENT;
+
 	idx = mt76_wcid_alloc(dev->mt76.wcid_mask, MT792x_WTBL_STA - 1);
 	if (idx < 0)
 		return -ENOSPC;
@@ -850,6 +853,9 @@ int mt7921_mac_sta_event(struct mt76_dev *mdev, struct ieee80211_vif *vif,
 	struct mt792x_sta *msta = (struct mt792x_sta *)sta->drv_priv;
 	struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv;
 
+	if (sta->aid > MT7921_MAX_AID)
+		return -ENOENT;
+
 	if (ev != MT76_STA_EVENT_ASSOC)
 	    return 0;
 
diff --git a/mt7921/mt7921.h b/mt7921/mt7921.h
index c88793fc..faa0d939 100644
--- a/mt7921/mt7921.h
+++ b/mt7921/mt7921.h
@@ -7,6 +7,8 @@
 #include "../mt792x.h"
 #include "regs.h"
 
+#define MT7921_MAX_AID                  20
+
 #define MT7921_TX_RING_SIZE		2048
 #define MT7921_TX_MCU_RING_SIZE		256
 #define MT7921_TX_FWDL_RING_SIZE	128