diff --git a/env/merlin/spack.yaml b/env/merlin/spack.yaml
index 6285978..853b321 100644
--- a/env/merlin/spack.yaml
+++ b/env/merlin/spack.yaml
@@ -517,7 +517,7 @@ spack:
 #<<<
   specs:
     - matrix: 
-      - [cmake,cuda,fftw,gromacs,kokkos,mpich,nvhpc,openblas threads=none,openblas threads=openmp,
+      - [cmake,cuda,fftw,gromacs,kokkos,mpich netmod=ucx,nvhpc,openblas threads=none,openblas threads=openmp,
          python,root,slurm,gsl]
       - ['%gcc']
     - matrix: