diff --git a/pkgs/development/ocaml-modules/iri/default.nix b/pkgs/development/ocaml-modules/iri/default.nix
index 22f10697586..0ea05cb7b9b 100644
--- a/pkgs/development/ocaml-modules/iri/default.nix
+++ b/pkgs/development/ocaml-modules/iri/default.nix
@@ -5,7 +5,7 @@
 buildDunePackage rec {
   pname = "iri";
   version = "0.6.0";
-  useDune2 = true;
+  duneVersion = "3";
 
   src = fetchFromGitLab {
     domain = "framagit.org";