diff --git a/environments/hlrs/spack.yaml b/environments/hlrs/spack.yaml
index 9ec9395..158af28 100644
--- a/environments/hlrs/spack.yaml
+++ b/environments/hlrs/spack.yaml
@@ -18,6 +18,9 @@ spack:
       - [$cflags_noerror_implicit]    # code is not fully C99
       - [$^mpis]
       - [$%compilers]
+    - matrix:     # build tools
+      - [meson, ninja]
+      - [$%core_compiler]
   view: false
   concretizer:
     unify: when_possible