                ;; All fits in a single row.
                (values 1 nil))
               (t
-               (lusty--compute-optimal-layout-inner lengths-v)))
+               (lusty--compute-optimal-layout-inner lengths-v
+                                                    separator-length)))
       (let ((n-columns 0)
             (column-widths '()))
 

                lengths-v truncated-p)))))

;; Returns number of rows and whether this truncates the entries.
(defun* lusty--compute-optimal-layout-inner (lengths-v)
  (let* ((n-items (length lengths-v))
         (max-visible-rows (1- (lusty-max-window-height)))
         (available-width (lusty-max-window-width))


            (push column-width column-widths)
            (incf total-width column-width)
            (incf total-width separator-length))

          (incf col-start-index n-rows) ; setq col-end-index
          (incf col-end-index n-rows)
