diff --git a/src/dune b/src/dune
index 677df3c..57405fe 100644
--- a/src/dune
+++ b/src/dune
@@ -49,4 +49,4 @@
  (targets ocamlopt-flags)
  (deps)
  (action
-  (bash "echo '()' > ocamlopt-flags")))
+  (with-stdout-to ocamlopt-flags (echo "()"))))