diff --git a/config/nvim/lua/plugins/guard.lua b/config/nvim/lua/plugins/guard.lua
index 388aa9a..c996e96 100644
--- a/config/nvim/lua/plugins/guard.lua
+++ b/config/nvim/lua/plugins/guard.lua
@@ -39,8 +39,9 @@ return {
         ft('cpp'):lint('cpplint')
         ft('markdown'):fmt('cbfmt'):append('prettierd')
         ft('nix'):fmt({
-            cmd = 'nixfmt',
-            stdin = true,
+            cmd = 'nix',
+            args = { 'fmt', '--' },
+            fname = true,
         })
     end,
 }