diff --git a/mt7603.h b/mt7603.h
index 0571c0d7..45e85005 100644
--- a/mt7603.h
+++ b/mt7603.h
@@ -20,6 +20,7 @@
 #define MT7603_MAX_INTERFACES	4
 #define MT7603_WTBL_SIZE	128
 #define MT7603_WTBL_RESERVED	(MT7603_WTBL_SIZE - 1)
+#define MT7603_WTBL_STA		(MT7603_WTBL_RESERVED - MT7603_MAX_INTERFACES)
 
 #define MT7603_RATE_RETRY	2
 
diff --git a/mt7603_main.c b/mt7603_main.c
index 1396b37b..b69c3c13 100644
--- a/mt7603_main.c
+++ b/mt7603_main.c
@@ -221,7 +221,7 @@ mt7603_sta_add(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 
 	mutex_lock(&dev->mutex);
 
-	idx = mt76_wcid_alloc(dev->wcid_mask, ARRAY_SIZE(dev->wcid) - 1);
+	idx = mt76_wcid_alloc(dev->wcid_mask, MT7603_WTBL_STA - 1);
 	if (idx < 0) {
 		ret = -ENOSPC;
 		goto out;