diff --git a/pkgs/development/ocaml-modules/ocaml-monadic/default.nix b/pkgs/development/ocaml-modules/ocaml-monadic/default.nix
index 0420e95b12b..69fa4cba851 100644
--- a/pkgs/development/ocaml-modules/ocaml-monadic/default.nix
+++ b/pkgs/development/ocaml-modules/ocaml-monadic/default.nix
@@ -6,6 +6,8 @@ buildDunePackage rec {
   pname = "ocaml-monadic";
   version = "0.4.1";
 
+  useDune2 = true;
+
   src = fetchFromGitHub {
     owner = "zepalmer";
     repo = pname;