diff --git a/Compiler/openmpi/files/config.yaml b/Compiler/openmpi/files/config.yaml
index 44a5d31..0381a7b 100644
--- a/Compiler/openmpi/files/config.yaml
+++ b/Compiler/openmpi/files/config.yaml
@@ -63,6 +63,28 @@ openmpi:
           - --enable-mpi1-compatibility
           - --enable-static=no
       variants:
+        # Unstable
+        - systems: [.*.merlin7.psi.ch]
+          relstage: unstable
+          overlay: Alps
+          use_overlays: [PSI, Alps]
+          group_deps:
+            compiler: {gcc: [15.2.0,14.3.0,13.4.0,12.4.0]}
+          build_requires:
+            - hwloc/2.12.0
+            - patchelf/0.14.5
+            - shs-cassini-headers/12.0.1-oss
+            - shs-cxi-driver/12.0.1-oss
+            - shs-libcxi/12.0.1-oss
+          runtime_deps:
+            - cuda/12.9.1
+            - pmix/5.0.8
+            - libfabric/2.2.0-oss
+          configure_args+:
+            - --with-lustre
+            - --with-xpmem
+          use_flags: [merlin7, slurm]
+        # Stable
         - systems: [.*.merlin7.psi.ch]
           relstage: stable
           overlay: Alps