diff --git a/mes/module/mes/boot-6.mes b/mes/module/mes/boot-6.mes
index 0450ba39..17ae02d5 100644
--- a/mes/module/mes/boot-6.mes
+++ b/mes/module/mes/boot-6.mes
@@ -2005,10 +2005,14 @@
     (force-output cep)
     (throw 'abort key)))
 
+(define core:exit exit)
 (define (quit . args)
   (apply throw 'quit args))
 
-(define exit quit)
+;; FIXME: how does Guile exit 0?
+;; this gives
+;;    unhandled exception: error: (("option must be specified with argument:" "main"))
+;;(define exit quit)
 
 ;;(define has-shown-backtrace-hint? #f) Defined by scm_init_backtrace ()