diff --git a/drivers/net/wireless/realtek/rtw89/coex.c b/drivers/net/wireless/realtek/rtw89/coex.c
index 3a586a971e8f..bda0e1e99a8c 100644
--- a/drivers/net/wireless/realtek/rtw89/coex.c
+++ b/drivers/net/wireless/realtek/rtw89/coex.c
@@ -206,7 +206,7 @@ static const struct rtw89_btc_ver rtw89_btc_ver_defs[] = {
 struct rtw89_btc_btf_tlv {
 	u8 type;
 	u8 len;
-	u8 val[1];
+	u8 val[];
 } __packed;
 
 enum btc_btf_set_report_en {