diff --git a/autoload/indent_guides.vim b/autoload/indent_guides.vim
index 7804b5f..0d141cc 100644
--- a/autoload/indent_guides.vim
+++ b/autoload/indent_guides.vim
@@ -271,7 +271,7 @@ endfunction
 " Detect if any of the buffer filetypes should be excluded.
 "
 function! indent_guides#exclude_filetype()
-  for ft in split(&ft, ',')
+  for ft in split(&ft, '\.')
     if index(g:indent_guides_exclude_filetypes, ft) > -1
       return 1
     end