diff --git a/flake.lock b/flake.lock
index a8e8e792ea9363da1b9aaa0aa9142164918f9bce..62f346895a34eb81b05d0c4b8ce993b8c9de6d00 100644
--- a/flake.lock
+++ b/flake.lock
@@ -23,11 +23,11 @@
     },
     "bscpkgs": {
       "locked": {
-        "lastModified": 1682521628,
-        "narHash": "sha256-uRIDCuJNt3rdikWiRcM3VPsQSk0vpQB1JO3Wx24psJo=",
+        "lastModified": 1686927936,
+        "narHash": "sha256-y9/R5OqDRFeq5kKRAsv9gge7vkeF/g1ImlbivpjYP/4=",
         "ref": "refs/heads/master",
-        "rev": "c775ee4d6f76aded05b08ae13924c302f18f9b2c",
-        "revCount": 807,
+        "rev": "cbe9af5d042e9d5585fe2acef65a1347c68b2fbd",
+        "revCount": 834,
         "type": "git",
         "url": "https://pm.bsc.es/gitlab/rarias/bscpkgs.git"
       },
diff --git a/m/common/main.nix b/m/common/main.nix
index ba503760a0ad769ede9b80494d9042046f3578df..f8622b146202ed429f17434233d6fcd3787e0473 100644
--- a/m/common/main.nix
+++ b/m/common/main.nix
@@ -11,7 +11,10 @@
     ./users.nix
   ];
 
-  nixpkgs.overlays = [ bscpkgs.bscOverlay ];
+  nixpkgs.overlays = [
+    bscpkgs.bscOverlay
+    (import ../../pkgs/mpi.nix)
+  ];
 
   nix.nixPath = [
     "nixpkgs=${nixpkgs}"
@@ -32,6 +35,8 @@
     vim wget git htop tmux pciutils tcpdump ripgrep nix-index nixos-option
     nix-diff ipmitool freeipmi ethtool lm_sensors ix cmake gnumake file tree
     ncdu
+    # From bsckgs overlay
+    bsc.osumb
   ];
 
   systemd.services."serial-getty@ttyS0" = {
diff --git a/m/common/slurm.nix b/m/common/slurm.nix
index 650156fa2abc962357c009768c020b7bb97ddfed..ce909dfd32c74668f6e84d028144a39229c597fe 100644
--- a/m/common/slurm.nix
+++ b/m/common/slurm.nix
@@ -10,7 +10,15 @@
       "hut       Sockets=2 CoresPerSocket=14 ThreadsPerCore=2"
     ];
     extraConfig = ''
+      # Use PMIx for MPI by default. It works okay with MPICH and OpenMPI, but
+      # not with Intel MPI. For that use the compatibility shim libpmi.so
+      # setting I_MPI_PMI_LIBRARY=$pmix/lib/libpmi.so while maintaining the PMIx
+      # library in SLURM (--mpi=pmix). See more details here:
+      # https://pm.bsc.es/gitlab/rarias/jungle/-/issues/16
       MpiDefault=pmix
+
+      # When a node reboots return that node to the slurm queue as soon as it
+      # becomes operative again.
       ReturnToService=2
     '';
   };
diff --git a/pkgs/mpi.nix b/pkgs/mpi.nix
new file mode 100644
index 0000000000000000000000000000000000000000..cdaeadda18f052cfed94a7158278b03d6748d3d3
--- /dev/null
+++ b/pkgs/mpi.nix
@@ -0,0 +1,25 @@
+final: prev:
+{
+  bsc = prev.bsc.extend (bscFinal: bscPrev: {
+    mpi = bscFinal.mpich;
+    mpich = with final; prev.mpich.overrideAttrs (old: {
+      buildInput = old.buildInputs ++ [
+        libfabric
+        pmix
+      ];
+      configureFlags = [
+        "--enable-shared"
+        "--enable-sharedlib"
+        "--with-pm=no"
+        "--with-device=ch4:ofi"
+        "--with-pmi=pmix"
+        "--with-pmix=${final.pmix}"
+        "--with-libfabric=${final.libfabric}"
+        "--enable-g=log"
+      ] ++ lib.optionals (lib.versionAtLeast gfortran.version "10") [
+        "FFLAGS=-fallow-argument-mismatch" # https://github.com/pmodels/mpich/issues/4300
+        "FCFLAGS=-fallow-argument-mismatch"
+      ];
+    });
+  });
+}