diff --git a/runtime/indent/verilog.vim b/runtime/indent/verilog.vim
index e81197c..377615c 100644
--- a/runtime/indent/verilog.vim
+++ b/runtime/indent/verilog.vim
@@ -1,6 +1,7 @@
 " Language:     Verilog HDL
 " Maintainer:	Chih-Tsun Huang <cthuang@cs.nthu.edu.tw>
 " Last Change:	2017 Aug 25 by Chih-Tsun Huang
+" 		2023 Aug 28 by Vim Project (undo_indent)
 " URL:		    http://www.cs.nthu.edu.tw/~cthuang/vim/indent/verilog.vim
 "
 " Credits:
@@ -28,6 +29,8 @@
 setlocal indentkeys+==endconfig,=endgenerate,=endprimitive,=endtable
 setlocal indentkeys+==`else,=`elsif,=`endif
 
+let b:undo_indent = "setlocal indentexpr< indentkeys<"
+
 " Only define the function once.
 if exists("*GetVerilogIndent")
   finish