diff --git a/env/sles15/x86_64/admin/unstable/spack.yaml b/env/sles15/x86_64/admin/unstable/spack.yaml
index db89b27..97205ba 100644
--- a/env/sles15/x86_64/admin/unstable/spack.yaml
+++ b/env/sles15/x86_64/admin/unstable/spack.yaml
@@ -10,8 +10,6 @@ spack:
   upstreams:
     spack-instance-1:
       install_tree: $spack/opt/spack/stable
-  include_concrete:
-  - $spack/spack-psi/env/$os/$target_family/admin/testing
   include:
   - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
   - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml