diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index dc0f7d9a992c..2ccf83837134 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -831,7 +831,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 	/* Enter report */
 	if ((data[1] & 0xfc) == 0xc0) {
 		/* serial number of the tool */
-		wacom->serial[idx] = ((data[3] & 0x0f) << 28) +
+		wacom->serial[idx] = ((__u64)(data[3] & 0x0f) << 28) +
 			(data[4] << 20) + (data[5] << 12) +
 			(data[6] << 4) + (data[7] >> 4);