diff --git a/m/common/main.nix b/m/common/main.nix
index 7054495..5d77ddc 100644
--- a/m/common/main.nix
+++ b/m/common/main.nix
@@ -14,7 +14,7 @@
 
   nixpkgs.overlays = [
     bscpkgs.bscOverlay
-    (import ../../pkgs/mpi.nix)
+    (import ../../pkgs/overlay.nix)
   ];
 
   nix.nixPath = [
diff --git a/pkgs/mpi.nix b/pkgs/overlay.nix
similarity index 91%
rename from pkgs/mpi.nix
rename to pkgs/overlay.nix
index cdaeadd..b86d2d9 100644
--- a/pkgs/mpi.nix
+++ b/pkgs/overlay.nix
@@ -1,7 +1,10 @@
 final: prev:
 {
   bsc = prev.bsc.extend (bscFinal: bscPrev: {
+    # Set MPICH as default
     mpi = bscFinal.mpich;
+
+    # Configure the network for MPICH
     mpich = with final; prev.mpich.overrideAttrs (old: {
       buildInput = old.buildInputs ++ [
         libfabric