diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f5d210f5b4d479f4a749ae3eb41cfd2e4cf2cef1..89eeae0efa083542100a41af74e3a4363c89dd7b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -354,9 +354,13 @@ install-stackspin:
   script:
     - *debug_information
     # Customize env file, remove all comments and empty lines
-    - >
-      sed "s/1.2.3.4/$IP_ADDRESS/; s/example.org/$FQDN/; s/acme_staging=false/acme_staging=true/; s/acme-v02/acme-staging-v02/; /^\s*#.*$/d; /^\s*$/d"
-        install/.flux.env.example >> ${CLUSTER_DIR}/.flux.env
+    - cp install/.flux.env.example ${CLUSTER_DIR}/.flux.env
+    - sed -i "s/1.2.3.4/$IP_ADDRESS/" ${CLUSTER_DIR}/.flux.env
+    - sed -i "s/example.org/$FQDN/"  ${CLUSTER_DIR}/.flux.env
+    - sed -i "s/acme_staging=false/acme_staging=true/" ${CLUSTER_DIR}/.flux.env
+    - sed -i "s/acme-v02/acme-staging-v02/;" ${CLUSTER_DIR}/.flux.env
+    - sed -i "/^\s*#.*$/d; /^\s*$/d" ${CLUSTER_DIR}/.flux.env
+    - cat ${CLUSTER_DIR}/.flux.env
     # Deploy secret/stackspin-cluster-variables
     - cp install/kustomization.yaml ${CLUSTER_DIR}
     - kubectl create namespace flux-system