diff --git a/lib/libc/sys/send.2 b/lib/libc/sys/send.2
index 003855281d5..6a61426bd7a 100644
--- a/lib/libc/sys/send.2
+++ b/lib/libc/sys/send.2
@@ -100,7 +100,6 @@ The
 argument may include one or more of the following:
 .Bd -literal
 #define	MSG_OOB		0x00001 /* process out-of-band data */
-#define	MSG_PEEK	0x00002 /* peek at incoming message */
 #define	MSG_DONTROUTE	0x00004 /* bypass routing, use direct interface */
 #define MSG_EOR		0x00008 /* data completes record */
 #define	MSG_EOF		0x00100 /* data completes transaction */