diff --git a/mt7915/mcu.c b/mt7915/mcu.c
index ebae157a..0c4ce537 100644
--- a/mt7915/mcu.c
+++ b/mt7915/mcu.c
@@ -622,7 +622,7 @@ mt7915_mcu_alloc_wtbl_req(struct mt7915_dev *dev, struct mt7915_sta *msta,
 	}
 
 	if (sta_hdr)
-		sta_hdr->len = cpu_to_le16(sizeof(hdr));
+		le16_add_cpu(&sta_hdr->len, sizeof(hdr));
 
 	return skb_put_data(nskb, &hdr, sizeof(hdr));
 }