diff --git a/pkgs/development/compilers/mosml/default.nix b/pkgs/development/compilers/mosml/default.nix
index 89726f20c6b8..b22072651a46 100644
--- a/pkgs/development/compilers/mosml/default.nix
+++ b/pkgs/development/compilers/mosml/default.nix
@@ -6,7 +6,7 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ gmp perl ];
 
-  makeFlags = "PREFIX=$(out)";
+  makeFlags = [ "PREFIX=$(out)" ] ++ stdenv.lib.optionals stdenv.isDarwin [ "CC=cc" ];
 
   src = fetchurl {
     url = "https://github.com/kfl/mosml/archive/ver-${version}.tar.gz";
@@ -23,7 +23,7 @@ stdenv.mkDerivation rec {
     '';
     homepage = https://mosml.org/;
     license = licenses.gpl2;
-    platforms = platforms.linux;
+    platforms = platforms.unix;
     maintainers = with maintainers; [ vaibhavsagar ];
   };
 }