diff --git a/pkgs/development/compilers/fstar/default.nix b/pkgs/development/compilers/fstar/default.nix
index 00714875ffc..51777f748e3 100644
--- a/pkgs/development/compilers/fstar/default.nix
+++ b/pkgs/development/compilers/fstar/default.nix
@@ -19,7 +19,8 @@ stdenv.mkDerivation rec {
   ];
 
   preBuild = ''
-    substituteInPlace src/Makefile --replace "\$(RUNTIME) VS/.nuget/NuGet.exe" "true"
+    substituteInPlace src/Makefile --replace "\$(RUNTIME) VS/.nuget/NuGet.exe" "true" \
+      --replace Darwin xyz
     substituteInPlace src/VS/.nuget/NuGet.targets --replace "mono" "true"
 
     # Fails with bad interpreter otherwise