diff --git a/plugin/vimwiki.vim b/plugin/vimwiki.vim
index af43f83..8fe5f93 100644
--- a/plugin/vimwiki.vim
+++ b/plugin/vimwiki.vim
@@ -84,7 +84,7 @@ function! s:setup_buffer_enter() "{{{
     return
   endif
 
-  if &filetype == ''
+  if &filetype != 'vimwiki'
     setfiletype vimwiki
   endif