diff --git a/src/superio/nuvoton/nct6791d/superio.c b/src/superio/nuvoton/nct6791d/superio.c
index 91a39084a9..343dd13475 100644
--- a/src/superio/nuvoton/nct6791d/superio.c
+++ b/src/superio/nuvoton/nct6791d/superio.c
@@ -30,7 +30,8 @@ static const char *nct6791d_acpi_hid(const struct device *dev)
 		return NULL;
 
 	switch (dev->path.pnp.device & 0xff) {
-	case NCT6791D_SP1: /* fallthrough */
+	case NCT6791D_SP1:
+		__fallthrough;
 	case NCT6791D_SP2:
 		return ACPI_HID_COM;
 	case NCT6791D_KBC: