diff --git a/isabel/slurm/flake.nix b/isabel/slurm/flake.nix
index 6ca1285..662bc2d 100644
--- a/isabel/slurm/flake.nix
+++ b/isabel/slurm/flake.nix
@@ -3,15 +3,30 @@
   outputs = { self, bscpkgs }:  
   let
     nixpkgs = bscpkgs.inputs.nixpkgs;
+    clusterOverlay = (final: prev: {
+      # Use cluster llvm compiler repo
+      clangOmpss2Unwrapped = prev.clangOmpss2Unwrapped.override {
+        useGit = true;
+        gitUrl = "ssh://git@bscpm04.bsc.es/ompss-2-at-cluster/llvm.git";
+        gitCommit = "151c260ba834826c01855da0a41fc203ffe4d025";
+        gitBranch = "cluster";
+      };
+    });
     pkgs = import nixpkgs {
       system = "x86_64-linux";
-      overlays = [ bscpkgs.outputs.bscOverlay ];
+      overlays = [
+        # Apply bscpkgs to get our BSC custom packages
+        bscpkgs.outputs.bscOverlay
+        # And on top apply our local changes to customize for cluster
+        clusterOverlay
+      ];
     };
   in {
     devShells.x86_64-linux.default = pkgs.mkShell {
       pname = "devshell";
       buildInputs = with pkgs; [
         slurm.out slurm.dev gcc
+        stdenvClangOmpss2
       ];
       inputsFrom = with pkgs; [
         nanos6