diff --git a/lib/stack-lock.sh b/lib/stack-lock.sh
index bdeaddb..39cd929 100644
--- a/lib/stack-lock.sh
+++ b/lib/stack-lock.sh
@@ -126,7 +126,8 @@ stack_lock_acquire() {
         ;;
       held:*)
         local cur_holder="${status#held:}"
-        local remaining=$(( deadline - $(date -u +%s) ))
+        local remaining
+        remaining=$(( deadline - $(date -u +%s) ))
         if [ "$remaining" -le 0 ]; then
           echo "[stack-lock] timed out waiting for lock on ${project} (held by ${cur_holder})" >&2
           return 1