diff --git a/krl-mode.el b/krl-mode.el
index 6d2b19c..7f3b344 100644
--- a/krl-mode.el
+++ b/krl-mode.el
@@ -4,6 +4,8 @@
     (define-key map "\C-j" 'newline-and-indent)
     map)
   "Keymap for KRL major mode")
+(defvar krl-indent-offset 2
+  "Indentation step for nested KRL blocks.")
 
 (add-to-list 'auto-mode-alist '("\\.src\\'" . krl-mode))
 (add-to-list 'auto-mode-alist '("\\.dat\\'" . krl-mode))
@@ -267,13 +269,13 @@
           (setq ind 0))
          ((looking-at krl-indent-regex-toplevel-block-open)
           ;(message "found tlb open")
-          (setq ind (+ 2 (current-indentation))))
+          (setq ind (+ krl-indent-offset (current-indentation))))
          ((looking-at krl-indent-regex-nested-block-close)
           ;(message "found nb close")
           (setq ind (current-indentation)))
          ((looking-at krl-indent-regex-nested-block-open)
           ;(message "found nb open")
-          (setq ind (+ 2 (current-indentation))))
+          (setq ind (+ krl-indent-offset (current-indentation))))
          (t
           ;(message "found other")
           )