diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f2c7500ad9c6effbbea9797c951ae597cbceb296..b51a3e0f1a443a3a1c5cd2c8a97862c1a4071bf1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -141,10 +141,12 @@ spack:install_compilers:
       --show-log-on-error
       ${COMPILER_LIST_SPECS}
 
+    - hashes=$(jq -r '.spec.nodes | map("/\(.hash)") | join(" ")' compilers_spec.json)
+
     - spack/bin/spack buildcache create
       --update-index
       --key EDC904DCE3D2E84E
-      /buildcache $( jq -r '.spec.nodes | map("/\(.hash)") | join(" ")' compilers_spec.json )
+      /buildcache ${hashes}
 
     - |
       echo 'definitions: [ compilers: [' ${COMPILER_LIST_SPECS} ']]' > compiler_definitions.yaml