diff --git a/spack.yaml b/spack.yaml
index 8ec166244d9872a7148e9815461a3b9fd5d76dcc..5b1825c38fd924dcfd091db3a4fc1625eafa278c 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -41,7 +41,8 @@ spack:
     - stow@2.3.1
     - tensorflow-lite@2.8.0 -xnnpack
     - xrootd@5.1.0 cxxstd=17 +python
-  concretization: together
+  concretizer: 
+    unify: true
   packages:
     all:
       compiler: [gcc]