diff --git a/pkgs/development/ocaml-modules/mirage-block-ramdisk/default.nix b/pkgs/development/ocaml-modules/mirage-block-ramdisk/default.nix
index 78f3e48c5bd..a6978d3d581 100644
--- a/pkgs/development/ocaml-modules/mirage-block-ramdisk/default.nix
+++ b/pkgs/development/ocaml-modules/mirage-block-ramdisk/default.nix
@@ -16,6 +16,7 @@ buildDunePackage rec {
   '';
 
   minimalOCamlVersion = "4.06";
+  duneVersion = "3";
 
   propagatedBuildInputs = [ io-page mirage-block ];