diff --git a/include/sys/timex.h b/include/sys/timex.h
index 08f4b0946651ab0c4242a5dd40db9f133b22c52a..2e688880a8b2d71e905091161efa63a32601d53e 100644
--- a/include/sys/timex.h
+++ b/include/sys/timex.h
@@ -36,6 +36,7 @@ struct timex {
 #define ADJ_STATUS		0x0010
 #define ADJ_TIMECONST		0x0020
 #define ADJ_TAI			0x0080
+#define ADJ_SETOFFSET		0x0100
 #define ADJ_MICRO		0x1000
 #define ADJ_NANO		0x2000
 #define ADJ_TICK		0x4000