diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index 582860ac8764..5b06fa366098 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -388,7 +388,7 @@ static int whiteheat_attach (struct usb_serial *serial)
 	if (ret) {
 		err("%s: Couldn't send command [%d]", serial->type->description, ret);
 		goto no_firmware;
-	} else if (alen != sizeof(command)) {
+	} else if (alen != 2) {
 		err("%s: Send command incomplete [%d]", serial->type->description, alen);
 		goto no_firmware;
 	}
@@ -400,7 +400,7 @@ static int whiteheat_attach (struct usb_serial *serial)
 	if (ret) {
 		err("%s: Couldn't get results [%d]", serial->type->description, ret);
 		goto no_firmware;
-	} else if (alen != sizeof(result)) {
+	} else if (alen != sizeof(*hw_info) + 1) {
 		err("%s: Get results incomplete [%d]", serial->type->description, alen);
 		goto no_firmware;
 	} else if (result[0] != command[0]) {