diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 2e9e8271b28615d0a8e7dca9076aa1db1acc44af..725b39886cdd3d9fb3a5c14df2446789c10e654d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -90,6 +90,8 @@ spack:setup:
       fi
 
     - mkdir -p /stack/spack/etc
+    - 'echo "config: { install_tree: { root: /stack/spack/opt/spack } }" > /stack/spack/etc/config.yaml'
+
 
 
 spack:install_compilers: