diff --git a/mt7915/main.c b/mt7915/main.c
index df09b27f..e9de51e2 100644
--- a/mt7915/main.c
+++ b/mt7915/main.c
@@ -189,7 +189,8 @@ static int mt7915_add_interface(struct ieee80211_hw *hw,
 	phy->mt76->vif_mask |= BIT(mvif->idx);
 	phy->omac_mask |= BIT_ULL(mvif->omac_idx);
 
-	idx = MT7915_WTBL_RESERVED - mvif->idx;
+	idx = MT7915_WTBL_RESERVED - mvif->idx -
+	      ext_phy * MT7915_MAX_INTERFACES / 2;
 
 	INIT_LIST_HEAD(&mvif->sta.rc_list);
 	INIT_LIST_HEAD(&mvif->sta.stats_list);