diff --git a/pkgs/development/tools/build-managers/mill/default.nix b/pkgs/development/tools/build-managers/mill/default.nix
index 4fbd0365af9..27a21619c1d 100644
--- a/pkgs/development/tools/build-managers/mill/default.nix
+++ b/pkgs/development/tools/build-managers/mill/default.nix
@@ -2,11 +2,11 @@
 
 stdenv.mkDerivation rec {
   pname = "mill";
-  version = "0.9.6";
+  version = "0.9.9";
 
   src = fetchurl {
-    url = "https://github.com/com-lihaoyi/mill/releases/download/${version}/${version}";
-    sha256 = "sha256-cAhcTmSPkV5z5ryuCNrpxy9/1iWvvminiVYul9c/DwM=";
+    url = "https://github.com/com-lihaoyi/mill/releases/download/${version}/${version}-assembly";
+    sha256 = "sha256-HIT7bxMEz7jpSsYvohN9+zYuyCf/ARE7hd48YMTo9/4=";
   };
 
   nativeBuildInputs = [ makeWrapper ];
@@ -15,6 +15,9 @@ stdenv.mkDerivation rec {
   dontConfigure = true;
   dontBuild = true;
 
+  # this is mostly downloading a pre-built artifact
+  preferLocal = true;
+
   installPhase = ''
     runHook preInstall
     install -Dm555 "$src" "$out/bin/.mill-wrapped"
@@ -25,6 +28,13 @@ stdenv.mkDerivation rec {
     runHook postInstall
   '';
 
+  doInstallCheck = true;
+  # The default release is a script which will do an impure download
+  # just ensure that the application can run without network
+  installCheckPhase = ''
+    $out/bin/mill --help > /dev/null
+  '';
+
   meta = with lib; {
     homepage = "https://www.lihaoyi.com/mill";
     license = licenses.mit;