diff --git a/pkgs/development/ocaml-modules/fmt/default.nix b/pkgs/development/ocaml-modules/fmt/default.nix
index 4816cab57cfd..bd5629816528 100644
--- a/pkgs/development/ocaml-modules/fmt/default.nix
+++ b/pkgs/development/ocaml-modules/fmt/default.nix
@@ -14,8 +14,8 @@ stdenv.mkDerivation rec {
   };
 
   nativeBuildInputs = [ ocaml findlib ocamlbuild topkg ];
-  buildInputs = [ topkg ];
-  propagatedBuildInputs = [ cmdliner seq stdlib-shims ];
+  buildInputs = [ cmdliner topkg ];
+  propagatedBuildInputs = [ seq stdlib-shims ];
 
   strictDeps = true;
 
diff --git a/pkgs/development/ocaml-modules/ocaml-r/default.nix b/pkgs/development/ocaml-modules/ocaml-r/default.nix
index fcee63de3b5d..ed22177bfaac 100644
--- a/pkgs/development/ocaml-modules/ocaml-r/default.nix
+++ b/pkgs/development/ocaml-modules/ocaml-r/default.nix
@@ -37,6 +37,8 @@ buildDunePackage rec {
   checkInputs = [ alcotest ];
 
   meta = {
+    # This has been broken by the update to R 4.2.0 (#171597)
+    broken = true;
     description = "OCaml bindings for the R interpreter";
     inherit (src.meta) homepage;
     license = lib.licenses.gpl3;
diff --git a/pkgs/development/ocaml-modules/parmap/default.nix b/pkgs/development/ocaml-modules/parmap/default.nix
index 521c1c406714..18e1975b698d 100644
--- a/pkgs/development/ocaml-modules/parmap/default.nix
+++ b/pkgs/development/ocaml-modules/parmap/default.nix
@@ -10,13 +10,12 @@ buildDunePackage rec {
   };
 
   minimalOCamlVersion = "4.03";
-  useDune2 = true;
 
   buildInputs = [
     dune-configurator
   ];
 
-  doCheck = true;
+  doCheck = false; # prevent running slow benchmarks
 
   meta = with lib; {
     description = "Library for multicore parallel programming";