diff --git a/runtime/ftplugin/calendar.vim b/runtime/ftplugin/calendar.vim
index f454ba1..c4e683a 100644
--- a/runtime/ftplugin/calendar.vim
+++ b/runtime/ftplugin/calendar.vim
@@ -2,6 +2,7 @@
 " Language:             calendar(1) input file
 " Previous Maintainer:  Nikolai Weibull <now@bitwi.se>
 " Latest Revision:      2008-07-09
+"                       2024-06-02 by Riley Bruins <ribru17@gmail.com> ('commentstring')
 
 if exists("b:did_ftplugin")
   finish
@@ -13,7 +14,7 @@
 
 let b:undo_ftplugin = "setl com< cms< inc< fo<"
 
-setlocal comments=s1:/*,mb:*,ex:*/ commentstring& include&
+setlocal comments=s1:/*,mb:*,ex:*/ commentstring=/*\ %s\ */ include&
 setlocal formatoptions-=t formatoptions+=croql
 
 let &cpo = s:cpo_save