diff --git a/README b/README
index de1b0f4426..944e76165f 100644
--- a/README
+++ b/README
@@ -74,6 +74,8 @@ Building
 	of the following systems:
 
 		Slackware Linux 7.0 with 2.4.0-test6 kernel and glibc 2.1.3
+		UnixWare 7.1.2 once the IN6_IS_ADDR_MULTICAST macro in
+			/usr/include/netinet/in6_f.h is repaired (== vs =).
 
 	To build, just