diff --git a/vimrc b/vimrc
index 7682c59..cb53a44 100644
--- a/vimrc
+++ b/vimrc
@@ -124,6 +124,8 @@ let g:haskell_conceal              = 0
 
 au syntax tex setl iskeyword+=:
 let g:syntastic_tex_checkers=['lacheck']
+call tcomment#DefineType('nix', '# %s')
+
 " better paragraph object for tex files FIXME
 call textobj#user#plugin('latexparagraph', {
 \   'paragraph': {