diff --git a/newlib/libc/sys/rtems/include/netinet/tcp.h b/newlib/libc/sys/rtems/include/netinet/tcp.h
index 4e06c9792..528f3cd8d 100644
--- a/newlib/libc/sys/rtems/include/netinet/tcp.h
+++ b/newlib/libc/sys/rtems/include/netinet/tcp.h
@@ -71,8 +71,9 @@ struct tcphdr {
 #define	TH_URG	0x20
 #define	TH_ECE	0x40
 #define	TH_CWR	0x80
+#define	TH_AE	0x100			/* maps into th_x2 */
 #define	TH_FLAGS	(TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG|TH_ECE|TH_CWR)
-#define	PRINT_TH_FLAGS	"\20\1FIN\2SYN\3RST\4PUSH\5ACK\6URG\7ECE\10CWR"
+#define	PRINT_TH_FLAGS	"\20\1FIN\2SYN\3RST\4PUSH\5ACK\6URG\7ECE\10CWR\11AE"
 
 	u_short	th_win;			/* window */
 	u_short	th_sum;			/* checksum */