diff --git a/env/merlin/spack.yaml b/env/merlin/spack.yaml
index e07a801..939c7ad 100644
--- a/env/merlin/spack.yaml
+++ b/env/merlin/spack.yaml
@@ -9,6 +9,8 @@ spack:
       - '%intel@2021.6.0'
       - '%nvhpc@21.5'
       - '%oneapi@2022.1.0'
+    # Careful!! Any external packages shouldn't be placed here, otherwise there is a possibility
+    # they'll end with a module pointing to empty paths!!
     - Batchsystem_pckgs: &Batchsystem_pckgs
         - slurm
     - Compiler_pckgs: &Compiler_pckgs