diff --git a/autoload/vimwiki/vars.vim b/autoload/vimwiki/vars.vim
index d93ef6a..bfa3177 100644
--- a/autoload/vimwiki/vars.vim
+++ b/autoload/vimwiki/vars.vim
@@ -361,6 +361,7 @@ function! s:populate_wikilocal_options() abort
         \ 'auto_toc': {'type': type(0), 'default': 0, 'min': 0, 'max': 1},
         \ 'automatic_nested_syntaxes': {'type': type(0), 'default': 1, 'min': 0, 'max': 1},
         \ 'base_url': {'type': type(''), 'default': '', 'min_length': 1},
+        \ 'commentstring': {'type': type(''), 'default': '%%%s'},
         \ 'css_name': {'type': type(''), 'default': 'style.css', 'min_length': 1},
         \ 'custom_wiki2html': {'type': type(''), 'default': ''},
         \ 'custom_wiki2html_args': {'type': type(''), 'default': ''},
diff --git a/ftplugin/vimwiki.vim b/ftplugin/vimwiki.vim
index 7c7cc74..97a2e08 100644
--- a/ftplugin/vimwiki.vim
+++ b/ftplugin/vimwiki.vim
@@ -9,13 +9,6 @@ if exists('b:did_ftplugin')
 endif
 let b:did_ftplugin = 1  " Don't load another plugin for this buffer
 
-" Enable/disable commentstring %%%s
-if !exists('g:vimwiki_commentstring')
-    setlocal commentstring=%%%s
-elseif g:vimwiki_commentstring != ""
-    let &l:commentstring=g:vimwiki_commentstring
-endif
-
 if vimwiki#vars#get_global('conceallevel') && exists('+conceallevel')
   let &l:conceallevel = vimwiki#vars#get_global('conceallevel')
 endif
@@ -142,6 +135,10 @@ if v:version > 703
   setlocal formatoptions+=j
 endif
 
+" Set commentstring %%%s
+let &l:commentstring = vimwiki#vars#get_wikilocal('commentstring')
+
+
 let &formatlistpat = vimwiki#vars#get_wikilocal('rxListItem')
 
 
diff --git a/test/commentstring.vader b/test/commentstring.vader
index 9d8ccc9..a216cef 100644
--- a/test/commentstring.vader
+++ b/test/commentstring.vader
@@ -1,4 +1,13 @@
-Include: vader_includes/vader_setup.vader
+# Test comment string PR #946
+# TODO try default 
+# TODO try editing other buffer
+#Execute (default commenstring, ft vimwiki):
+#  AssertEqual &filetype[0], 't'
+#  AssertEqual '/*%s*/', &commentstring
+
+
+Given txt (txt):
+  txt
 
 After (clean up):
   if exists('g:vimwiki_commentstring')
@@ -8,22 +17,16 @@ After (clean up):
     unlet b:did_ftplugin
   endif
 
-Execute (default commentstring):
-  AssertEqual '/*%s*/', &commentstring
-
-Execute (default commenstring, ft vimwiki):
-  let g:vimwiki_commentstring=""
-  set ft=vimwiki
-  AssertEqual '/*%s*/', &commentstring
-
 Execute (default vimwiki commentstring):
+  call vimwiki#vars#init()
   set ft=vimwiki
   AssertEqual '%%%s', &commentstring
 
 Execute (html commentstring):
   let g:vimwiki_commentstring='<!-- %s -->'
+  call vimwiki#vars#init()
   set ft=vimwiki
   AssertEqual '<!-- %s -->', &commentstring
 
-Include: vader_includes/vader_teardown.vader
-
+Expect (void):
+  txt