diff --git a/src/fileio.c b/src/fileio.c
index f9838396746..20a81c2a60f 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -3175,8 +3175,9 @@ See `file-symlink-p' to distinguish symlinks.  */)
 }
 
 DEFUN ("file-accessible-directory-p", Ffile_accessible_directory_p, Sfile_accessible_directory_p, 1, 1, 0,
-       doc: /* Return t if file FILENAME is the name of a directory as a file,
-and files in that directory can be opened by you.  In order to use a
+       doc: /* Return t if file FILENAME names a directory you can open.
+For the value to be t, FILENAME must specify the name of a directory as a file,
+and the directory must allow you to open files in it.  In order to use a
 directory as a buffer's current directory, this predicate must return true.
 A directory name spec may be given instead; then the value is t
 if the directory so specified exists and really is a readable and