diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 844401b5441079b1030c6738d37823b768d3ff27..4a6a8e93f1ac13386e3b9229920970f62a43b6f3 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -68,7 +68,7 @@ variables:
         SQUASHFS_ID: ${CI_COMMIT_BRANCH}
     - if: $CI_COMMIT_TAG =~ /^v[0-9].*$/
       variables:
-        SQUASHFS_ID: ${CI_COMMIT_BRANCH}
+        SQUASHFS_ID: ${CI_COMMIT_REF_SLUG}
 
 .parallel_job:
   extends:
diff --git a/ci/prepare_squashfs.sh b/ci/prepare_squashfs.sh
index 43deb47c488445ea4d8c5622a7b04a287dba3111..4914eaf4556d49788718c3ecb6d1f6a5b33688ab 100755
--- a/ci/prepare_squashfs.sh
+++ b/ci/prepare_squashfs.sh
@@ -5,7 +5,7 @@ set -o nounset
 set -o errexit
 source ${CI_PROJECT_DIR}/ci/stack_env.sh
 
-mkdir ${CI_DATA_ST}/homes
+mkdir -p ${CI_DATA_ST}/homes
 
 for i in squashfs-cache buildcache spack-mirror
 do