diff --git a/env/merlin/all/spack.yaml b/env/merlin/all/spack.yaml
index 3ff158e..6bf9d57 100644
--- a/env/merlin/all/spack.yaml
+++ b/env/merlin/all/spack.yaml
@@ -582,10 +582,10 @@ spack:
       link: all
       link_type: symlink
       projections: &unified_projections
-        ^mpi: '{name}/{version}/{^mpi.name}/{^mpi.version}/{compiler.name}/{compiler.version}'
-        all: '{name}/{version}/{compiler.name}/{compiler.version}'
-        ~mpi: '{name}_serial/{version}/{compiler.name}/{compiler.version}'
-        threads=openmp: '{name}_OMP/{version}/{compiler.name}/{compiler.version}'
+        ^mpi: '{name}/{version}/{^mpi.name}/{^mpi.version}/{compiler.name}/{compiler.version}/{hash}'
+        all: '{name}/{version}/{compiler.name}/{compiler.version}/{hash}'
+        ~mpi: '{name}_serial/{version}/{compiler.name}/{compiler.version}/{hash}'
+        threads=openmp: '{name}_OMP/{version}/{compiler.name}/{compiler.version}/{hash}'
       root: /afs/psi.ch/sys/spack-rhel7/Batchsystem
       select: *Batchsystem_pckgs
     Compiler: