diff --git a/lib/ChangeLog b/lib/ChangeLog
index 2d5f4f252..c44bac5ab 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,7 @@
+2000-11-09  Paul Eggert  <eggert@twinsun.com>
+
+	* lib/unicodeio.c (ENOTSUP): Define to EINVAL if not defined.
+
 2000-11-09  Paul Eggert  <eggert@twinsun.com>
 
 	* lib/unicodeio.c (MB_LEN_MAX): Make sure it's at least 6,