diff --git a/pkgs/development/ocaml-modules/alcotest/default.nix b/pkgs/development/ocaml-modules/alcotest/default.nix
index 0e459315fa88..d8310ce23eea 100644
--- a/pkgs/development/ocaml-modules/alcotest/default.nix
+++ b/pkgs/development/ocaml-modules/alcotest/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildDunePackage, fetchurl
+{ lib, buildDunePackage, fetchurl, fetchpatch
 , astring, cmdliner, fmt, re, stdlib-shims, uutf, ocaml-syntax-shims
 }:
 
@@ -6,13 +6,17 @@ buildDunePackage rec {
   pname = "alcotest";
   version = "1.7.0";
 
-  duneVersion = "3";
-
   src = fetchurl {
     url = "https://github.com/mirage/alcotest/releases/download/${version}/alcotest-${version}.tbz";
     hash = "sha256-gSus2zS0XoiZXgfXMGvasvckee8ZlmN/HV0fQWZ5At8=";
   };
 
+  # Fix tests with OCaml 5.2
+  patches = fetchpatch {
+    url = "https://github.com/mirage/alcotest/commit/aa437168b258db97680021116af176c55e1bd53b.patch";
+    hash = "sha256-cytuJFg4Mft47LsAEcz2zvzyy1wNzMdeLK+cjaFANpo=";
+  };
+
   nativeBuildInputs = [ ocaml-syntax-shims ];
 
   propagatedBuildInputs = [ astring cmdliner fmt re stdlib-shims uutf ];
diff --git a/pkgs/development/ocaml-modules/ppx_tools/default.nix b/pkgs/development/ocaml-modules/ppx_tools/default.nix
index 7a07daf8ddcd..41db9313fe7f 100644
--- a/pkgs/development/ocaml-modules/ppx_tools/default.nix
+++ b/pkgs/development/ocaml-modules/ppx_tools/default.nix
@@ -1,5 +1,9 @@
 { lib, stdenv, fetchFromGitHub, buildDunePackage, ocaml, findlib, cppo }:
 
+if lib.versionAtLeast ocaml.version "5.2"
+then throw "ppx_tools is not available for OCaml ${ocaml.version}"
+else
+
 let param =
   let v6_6 = {
     version = "6.6";
@@ -58,7 +62,6 @@ then
   buildDunePackage {
     inherit pname src meta;
     inherit (param) version buildInputs nativeBuildInputs;
-    duneVersion = "3";
   }
 else
   stdenv.mkDerivation {