diff --git a/runtime/indent/asm.vim b/runtime/indent/asm.vim
index 4efa766..054612b 100644
--- a/runtime/indent/asm.vim
+++ b/runtime/indent/asm.vim
@@ -13,7 +13,7 @@
 setlocal indentexpr=s:getAsmIndent()
 setlocal indentkeys=<:>,!^F,o,O
 
-let b:undo_indent = "indentexpr< indentkeys<"
+let b:undo_indent = "setlocal indentexpr< indentkeys<"
 
 function! s:getAsmIndent()
   let line = getline(v:lnum)