diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5f3367f07f5d80268e5ccc09fb2986d04f6ffb7d..73f5357e19f0b013b763c281a14735a20a1748e4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -15,9 +15,9 @@ workflow:
     - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
 
 variables:
-  BUILDCACHE: /scratch/richart/buildcache
-  SPACK_DISABLE_LOCAL_CONFIG: true
-  SPACK_USER_CACHE_PATH: /tmp/spack_cache
+  BUILDCACHE: "/scratch/richart/buildcache"
+  SPACK_DISABLE_LOCAL_CONFIG: "true"
+  SPACK_USER_CACHE_PATH: "/tmp/spack_cache"
 
 # ------------------------------------------------------------------------------
 .parallel_job: