diff --git a/autoload/airline/extensions/wordcount/formatters/default.vim b/autoload/airline/extensions/wordcount/formatters/default.vim
index a2b39351..6f1bae79 100644
--- a/autoload/airline/extensions/wordcount/formatters/default.vim
+++ b/autoload/airline/extensions/wordcount/formatters/default.vim
@@ -3,14 +3,17 @@
 
 scriptencoding utf-8
 
-function s:update_fmt(...)
+function! s:update_fmt(...)
   let s:fmt = get(g:, 'airline#extensions#wordcount#formatter#default#fmt', '%s words')
   let s:fmt_short = get(g:, 'airline#extensions#wordcount#formatter#default#fmt_short', s:fmt == '%s words' ? '%sW' : s:fmt)
 endfunction
 
 " Reload format when statusline is rebuilt
 call s:update_fmt()
-call airline#add_statusline_funcref(function('s:update_fmt'))
+if index(g:airline_statusline_funcrefs, function('s:update_fmt')) == -1
+  " only add it, if not already done
+  call airline#add_statusline_funcref(function('s:update_fmt'))
+endif
 
 if match(get(v:, 'lang', ''), '\v\cC|en') > -1
   let s:decimal_group = ','