diff --git a/plugin/gitgutter.vim b/plugin/gitgutter.vim
index b1f2528..c333762 100644
--- a/plugin/gitgutter.vim
+++ b/plugin/gitgutter.vim
@@ -18,6 +18,8 @@ if !exists('g:gitgutter_sign_column_always')
   let g:gitgutter_sign_column_always = 0
 endif
 
+let s:file = ''
+
 function! s:init()
   if !exists('g:gitgutter_initialised')
     call s:define_sign_column_highlight()