diff --git a/lib/ChangeLog b/lib/ChangeLog
index 92fb2e373..934392e91 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,7 +1,8 @@
 2001-02-16  Paul Eggert  <eggert@twinsun.com>
 
 	* lib/alloca.c (malloc): Undef before defining, since stdlib.h
-	may have defined it.
+	may have defined it.  Needed for Encore Umax-3.0.9.16b systems.
+	Reported by Mark Hounschell via Paul Eggert.
 
 2001-02-07  Jim Meyering  <meyering@lucent.com>