diff --git a/xtrn/sbl/sbldefs.h b/xtrn/sbl/sbldefs.h
index 729bd08af07d6b51b977558525dc2674d44061dc..49fe58c3bdc4c8f51b31c42bcd20c072946d763b 100644
--- a/xtrn/sbl/sbldefs.h
+++ b/xtrn/sbl/sbldefs.h
@@ -42,6 +42,10 @@
 #define DESC_LINES	5
 #define DEF_LIST_FMT "NSTP"
 
+#ifndef IPPORT_TELNET
+#define IPPORT_TELNET 23
+#endif
+
 /* Misc bits */
 
 #define FROM_SMB	(1L<<0) 	/* BBS info imported from message base */