diff --git a/UPDATING b/UPDATING
index cb00e10d167b..b76ad0a7d437 100644
--- a/UPDATING
+++ b/UPDATING
@@ -31,6 +31,14 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 11.x IS SLOW:
 	disable the most expensive debugging functionality run
 	"ln -s 'abort:false,junk:false' /etc/malloc.conf".)
 
+20140922:
+	At svn r271982, The default linux compat kernel ABI has been adjusted
+	to 2.6.18 in support of the linux-c6 compat ports infrastructure
+	update.  If you wish to continue using the linux-f10 compat ports,
+	add compat.linux.osrelease=2.6.16 to your local sysctl.conf.  Users are
+	encouraged to update their linux-compat packages to linux-c6 during
+	their next update cycle.
+
 20140729:
 	The ofwfb driver, used to provide a graphics console on PowerPC when
 	using vt(4), no longer allows mmap() of all of physical memory. This