diff --git a/hints/darwin.sh b/hints/darwin.sh
index b9c8a88d9b8c..d1119003796f 100644
--- a/hints/darwin.sh
+++ b/hints/darwin.sh
@@ -149,7 +149,8 @@ dlext='bundle';
 usedl='define';
 
 # 10.4 can use dlopen.
-# 10.4 broke poll().
+# 10.4 broke poll(). - Apple bug number 3710161
+# https://lists.apple.com/archives/Darwin-dev/2005/May/msg00220.html
 case "$osvers" in
 [1-7].*)
     dlsrc='dl_dyld.xs';