diff --git a/pkgs/development/ocaml-modules/io-page/default.nix b/pkgs/development/ocaml-modules/io-page/default.nix
index b5762822240..79142f0e8d4 100644
--- a/pkgs/development/ocaml-modules/io-page/default.nix
+++ b/pkgs/development/ocaml-modules/io-page/default.nix
@@ -5,10 +5,11 @@ buildDunePackage rec {
   version = "3.0.0";
 
   minimalOCamlVersion = "4.08";
+  duneVersion = "3";
 
   src = fetchurl {
     url = "https://github.com/mirage/${pname}/releases/download/v${version}/${pname}-${version}.tbz";
-    sha256 = "sha256-DjbKdNkFa6YQgJDLmLsuvyrweb4/TNvqAiggcj/3hu4=";
+    hash = "sha256-DjbKdNkFa6YQgJDLmLsuvyrweb4/TNvqAiggcj/3hu4=";
   };
 
   nativeBuildInputs = [ pkg-config ];