diff --git a/runtime/indent/python.vim b/runtime/indent/python.vim
index 307b7f6..6681229 100644
--- a/runtime/indent/python.vim
+++ b/runtime/indent/python.vim
@@ -2,7 +2,7 @@
 " Language:		Python
 " Maintainer:		Bram Moolenaar <Bram@vim.org>
 " Original Author:	David Bustos <bustos@caltech.edu>
-" Last Change:		2021 May 26
+" Last Change:		2021 Sep 26
 
 " Only load this indent file when no other was loaded.
 if exists("b:did_indent")
@@ -17,6 +17,8 @@
 setlocal indentexpr=GetPythonIndent(v:lnum)
 setlocal indentkeys+=<:>,=elif,=except
 
+let b:undo_indent = "setl ai< inde< indk< lisp<"
+
 " Only define the function once.
 if exists("*GetPythonIndent")
   finish