#9018: os.path.normcase() now raises a TypeError if the argument is not str or bytes.
diff --git a/Doc/library/os.path.rst b/Doc/library/os.path.rst
index 8c720bf..c838983 100644
--- a/Doc/library/os.path.rst
+++ b/Doc/library/os.path.rst
@@ -201,6 +201,7 @@
Normalize the case of a pathname. On Unix and Mac OS X, this returns the
path unchanged; on case-insensitive filesystems, it converts the path to
lowercase. On Windows, it also converts forward slashes to backward slashes.
+ Raise a TypeError if the type of *path* is not ``str`` or ``bytes``.
.. function:: normpath(path)