diff --git a/pkgs/applications/science/logic/leo2/default.nix b/pkgs/applications/science/logic/leo2/default.nix
index 4087763aa0c5..a72444adbba0 100644
--- a/pkgs/applications/science/logic/leo2/default.nix
+++ b/pkgs/applications/science/logic/leo2/default.nix
@@ -31,6 +31,8 @@ stdenv.mkDerivation rec {
 
   buildFlags = [ "opt" ];
 
+  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-reserved-user-defined-literal";
+
   preInstall = "mkdir -p $out/bin";
 
   postInstall = ''
@@ -44,7 +46,7 @@ stdenv.mkDerivation rec {
   meta = with lib; {
     description = "A high-performance typed higher order prover";
     maintainers = [ maintainers.raskin ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
     license = licenses.bsd3;
     homepage = "http://www.leoprover.org/";
   };
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index d86808acf5d9..5ea14dcd365c 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -37168,7 +37168,7 @@ with pkgs;
   mathlibtools = with python3Packages; toPythonApplication mathlibtools;
 
   leo2 = callPackage ../applications/science/logic/leo2
-    { inherit (ocaml-ng.ocamlPackages_4_05) ocaml camlp4; };
+    { inherit (ocaml-ng.ocamlPackages_4_14_unsafe_string) ocaml camlp4; };
 
   leo3-bin = callPackage ../applications/science/logic/leo3/binary.nix {};