diff --git a/pkgs/development/ocaml-modules/pprint/default.nix b/pkgs/development/ocaml-modules/pprint/default.nix
index 1ffb3e4e2d66..3a103ad41ae6 100644
--- a/pkgs/development/ocaml-modules/pprint/default.nix
+++ b/pkgs/development/ocaml-modules/pprint/default.nix
@@ -4,7 +4,7 @@ buildDunePackage rec {
   pname = "pprint";
   version = "20230830";
 
-  useDune2 = true;
+  minimalOCamlVersion = "4.03";
 
   src = fetchFromGitHub {
     owner = "fpottier";
diff --git a/pkgs/development/ocaml-modules/zelus-gtk/default.nix b/pkgs/development/ocaml-modules/zelus-gtk/default.nix
index c0e0e586066a..759a625d26a2 100644
--- a/pkgs/development/ocaml-modules/zelus-gtk/default.nix
+++ b/pkgs/development/ocaml-modules/zelus-gtk/default.nix
@@ -7,7 +7,7 @@ buildDunePackage {
   pname = "zelus-gtk";
   inherit (zelus) version src postPatch;
 
-  minimalOCamlVersion = "4.08.1";
+  minimalOCamlVersion = "4.10";
 
   nativeBuildInputs = [
     zelus