diff --git a/runtime/ftplugin/ishd.vim b/runtime/ftplugin/ishd.vim
index 5e33efde78..5525cb6cde 100644
--- a/runtime/ftplugin/ishd.vim
+++ b/runtime/ftplugin/ishd.vim
@@ -2,7 +2,8 @@
 " Language:		InstallShield (ft=ishd)
 " Maintainer:		Doug Kearns <dougkearns@gmail.com>
 " Previous Maintainer:	Johannes Zellner <johannes@zellner.org>
-" Last Change:		2024 Jan 14
+" Last Change:		2025 Jun 18
+" 2025 Jun 18 by Vim Project: set comments and commentstring option (#17490)
 
 if exists("b:did_ftplugin") | finish | endif
 let b:did_ftplugin = 1
@@ -12,8 +13,10 @@ let s:cpo_save = &cpo
 set cpo-=C
 
 setlocal foldmethod=syntax
+setlocal commentstring=//\ %s
+setlocal comments=sO:*\ -,mO:*\ \ ,exO:*/,s1:/*,mb:*,ex:*/,://
 
-let b:undo_ftplugin = "setl fdm<"
+let b:undo_ftplugin = "setl fdm< com< cms"
 
 " matchit support
 if exists("loaded_matchit")