diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index bd3a17942fa347..f0ecd96d939de3 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -1068,9 +1068,10 @@ string functions based on regular expressions.
 
 .. method:: str.join(iterable)
 
-   Return a string which is the concatenation of the strings in the
-   :term:`iterable` *iterable*.  The separator between elements is the string
-   providing this method.
+   Return a string which is the concatenation of the strings in *iterable*.
+   A :exc:`TypeError` will be raised if there are any non-string values in
+   *iterable*, including :class:`bytes` objects.  The separator between
+   elements is the string providing this method.
 
 
 .. method:: str.ljust(width[, fillchar])