diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
index 3bbf5c7e1500..3e4323a3918d 100644
--- a/include/uapi/linux/can/netlink.h
+++ b/include/uapi/linux/can/netlink.h
@@ -97,6 +97,7 @@ struct can_ctrlmode {
 #define CAN_CTRLMODE_ONE_SHOT		0x08	/* One-Shot mode */
 #define CAN_CTRLMODE_BERR_REPORTING	0x10	/* Bus-error reporting */
 #define CAN_CTRLMODE_FD			0x20	/* CAN FD mode */
+#define CAN_CTRLMODE_PRESUME_ACK	0x40	/* Ignore missing CAN ACKs */
 
 /*
  * CAN device statistics