diff --git a/libc/include/sys/socketcalls.h b/libc/include/sys/socketcalls.h
index 09c079f..131e0bb 100644
--- a/libc/include/sys/socketcalls.h
+++ b/libc/include/sys/socketcalls.h
@@ -48,5 +48,7 @@
 #define SYS_SENDMSG     16              /* sys_sendmsg(2)               */
 #define SYS_RECVMSG     17              /* sys_recvmsg(2)               */
 #define SYS_ACCEPT4     18              /* sys_accept4(2)               */
+#define SYS_RECVMMSG    19              /* sys_recvmmsg(2)              */
+#define SYS_SENDMMSG    20              /* sys_sendmmsg(2)              */
 
 #endif /* _SYS_SOCKETCALLS_H_ */