diff --git a/Doc/mac/libmacfs.tex b/Doc/mac/libmacfs.tex
index f6265ea..944ea1b 100644
--- a/Doc/mac/libmacfs.tex
+++ b/Doc/mac/libmacfs.tex
@@ -9,7 +9,8 @@
 \deprecated{2.3}{The macfs module should be considered obsolete. For
 \class{FSSpec}, \class{FSRef} and \class{Alias} handling use the
 \module{Carbon.File} or \refmodule{Carbon.Folder} module. For file
-dialogs use the \refmodule{EasyDialogs} module.}
+dialogs use the \refmodule{EasyDialogs} module.  Also, this module is
+known to not work correctly with UFS partitions.}
 
 This module provides access to Macintosh \class{FSSpec} handling, the
 Alias Manager, \program{finder} aliases and the Standard File package.
diff --git a/Doc/mac/libmacostools.tex b/Doc/mac/libmacostools.tex
index 06ddbc7..556e46f 100644
--- a/Doc/mac/libmacostools.tex
+++ b/Doc/mac/libmacostools.tex
@@ -8,7 +8,9 @@
 
 This module contains some convenience routines for file-manipulation
 on the Macintosh. All file parameters can be specified as
-pathnames, \class{FSRef} or \class{FSSpec} objects.
+pathnames, \class{FSRef} or \class{FSSpec} objects.  This module
+expects a filesystem which supports forked files, so it should not
+be used on UFS partitions.
 
 The \module{macostools} module defines the following functions: