diff --git a/src/ChangeLog b/src/ChangeLog
index 97401ffe40a..4d1225a112e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2010-12-13  Eli Zaretskii  <eliz@gnu.org>
+
+	* fileio.c (Fexpand_file_name): One more doc fix.
+
 2010-12-12  Eli Zaretskii  <eliz@gnu.org>
 
 	* fileio.c (Fexpand_file_name): Doc fix.  (Bug#7617)
diff --git a/src/fileio.c b/src/fileio.c
index e330f724142..da19c1e2a21 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -828,6 +828,8 @@ DEFUN ("expand-file-name", Fexpand_file_name, Sexpand_file_name, 1, 2, 0,
 Second arg DEFAULT-DIRECTORY is directory to start with if NAME is relative
 \(does not start with slash or tilde); if DEFAULT-DIRECTORY is nil or missing,
 the current buffer's value of `default-directory' is used.
+NAME should be a string that is a valid file name for the underlying
+filesystem.
 File name components that are `.' are removed, and
 so are file name components followed by `..', along with the `..' itself;
 note that these simplifications are done without checking the resulting