diff --git a/lab.sh b/lab.sh
index deb50ec..8653d12 100755
--- a/lab.sh
+++ b/lab.sh
@@ -595,6 +595,19 @@ with open(var_file, "w", encoding="utf-8") as handle:
 PY
 }
 
+prepare_cluster_worker_var_file() {
+    local include_raspberry_default="$1"
+    local spec_file="${REPO_ROOT}/.lab/manual-workers.tsv"
+    local var_file="${REPO_ROOT}/.lab/cluster-workers.auto.tfvars.json"
+
+    export LAB_INCLUDE_RASPBERRY_WORKER="${LAB_INCLUDE_RASPBERRY_WORKER:-${include_raspberry_default}}"
+
+    mkdir -p "${REPO_ROOT}/.lab"
+    : >"${spec_file}"
+    write_cluster_worker_var_file "${spec_file}" "${var_file}"
+    export LAB_CLUSTER_VAR_FILE="${var_file}"
+}
+
 run_pimox_pipeline() {
     local mode="${LAB_PIMOX_PIPELINE:-false}"
     local pimox_host="${LAB_PIMOX_HOST:-${TF_VAR_pimox_host:-192.168.100.80}}"
@@ -2486,6 +2499,7 @@ up() {
 
     deploy_gitea
     bootstrap_gitea_repo
+    prepare_cluster_worker_var_file true
     run_tofu_stack "bootstrap/cluster"
     run_tofu_stack "bootstrap/platform"
     apps
@@ -2497,12 +2511,12 @@ up() {
 rebuild_cluster() {
     require_debian_server "rebuild-cluster"
 
-    export LAB_INCLUDE_RASPBERRY_WORKER="${LAB_INCLUDE_RASPBERRY_WORKER:-false}"
     export WORKER_SSH_TARGETS="${WORKER_SSH_TARGETS:-}"
 
     echo "Rebuilding the Kubernetes cluster without touching external Raspberry Pi Gitea..."
 
     nuke
+    prepare_cluster_worker_var_file true
     run_tofu_stack "bootstrap/cluster"
     run_tofu_stack "bootstrap/platform"
     apps