diff --git a/src/soc/mediatek/common/mt6685.c b/src/soc/mediatek/common/mt6685.c
index 7d17556261..0d43c7bade 100644
--- a/src/soc/mediatek/common/mt6685.c
+++ b/src/soc/mediatek/common/mt6685.c
@@ -74,8 +74,8 @@ static const struct mt6685_key_setting key_protect_setting[] = {
 static void mt6685_unlock(bool unlock)
 {
 	for (int i = 0; i < ARRAY_SIZE(key_protect_setting); i++)
-		mt6685_write16(key_protect_setting[i].addr,
-			       unlock ? key_protect_setting[i].val : 0);
+		mt6685_write8(key_protect_setting[i].addr,
+			      unlock ? key_protect_setting[i].val : 0);
 }
 
 void mt6685_init_pmif_arb(void)