diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 3f89074aa06c..accbb1a231df 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -515,6 +515,10 @@ enum {
 	ETHTOOL_A_CABLE_RESULT_CODE_OPEN,
 	ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT,
 	ETHTOOL_A_CABLE_RESULT_CODE_CROSS_SHORT,
+	/* detected reflection caused by the impedance discontinuity between
+	 * a regular 100 Ohm cable and a part with the abnormal impedance value
+	 */
+	ETHTOOL_A_CABLE_RESULT_CODE_IMPEDANCE_MISMATCH,
 };
 
 enum {